Pure DEF or DEF+RES (Fire/Cold)

Would you rather have capped S/L, energy, and ranged?(my thought is the S,L,E will pick up most of what the ranged DEF misses). Or have capped ranged and around 50% S/L res to cut the ranged damage that gets through but allow more damage from melee and AOE?
Here are the two builds I have worked up.
DEF+RES build:
Villain Plan by Mids' Villain Designer 1.90
http://www.cohplanner.com/

Click this DataLink to open the build!

Level 50 Mutation Corruptor
Primary Power Set: Fire Blast
Secondary Power Set: Cold Domination
Power Pool: Speed
Power Pool: Leadership
Power Pool: Fighting
Power Pool: Leaping
Ancillary Pool: Leviathan Mastery

Villain Profile:
Level 1: Fire Blast -- Thundr-Acc/Dmg(A), Thundr-Dmg/EndRdx(3), Thundr-Dmg/Rchg(5), Thundr-Acc/Dmg/Rchg(31), Thundr-Acc/Dmg/EndRdx(31), Thundr-Dmg/EndRdx/Rchg(45)
Level 1: Infrigidate -- P'ngTtl-Acc/Slow(A)
Level 2: Fire Ball -- Posi-Acc/Dmg(A), Posi-Dmg/EndRdx(3), Posi-Dmg/Rchg(5), Posi-Dmg/Rng(15), Posi-Acc/Dmg/EndRdx(23)
Level 4: Snow Storm -- P'ngTtl-Acc/EndRdx(A), P'ngTtl--Rchg%(17), P'ngTtl-Acc/Slow(34), P'ngTtl-Dmg/Slow(39), P'ngTtl-Rng/Slow(40), P'ngTtl-EndRdx/Rchg/Slow(46)
Level 6: Rain of Fire -- Posi-Acc/Dmg(A), Posi-Dmg/EndRdx(7), Posi-Dmg/Rchg(7), RechRdx-I(13), Posi-Dmg/Rng(25), Posi-Acc/Dmg/EndRdx(27)
Level 8: Fire Breath -- Posi-Acc/Dmg(A), Posi-Dmg/EndRdx(9), Posi-Dmg/Rchg(9), Posi-Dmg/Rng(15), Posi-Acc/Dmg/EndRdx(25)
Level 10: Hasten -- RechRdx-I(A), RechRdx-I(11), RechRdx-I(11)
Level 12: Aim -- RechRdx-I(A), RechRdx-I(13)
Level 14: Maneuvers -- RedFtn-Def(A), RedFtn-Def/EndRdx(17), RedFtn-Def/Rchg(40), RedFtn-Def/EndRdx/Rchg(40), RedFtn-EndRdx(43), RedFtn-EndRdx/Rchg(43)
Level 16: Boxing -- Acc-I(A)
Level 18: Blaze -- Thundr-Acc/Dmg(A), Thundr-Dmg/EndRdx(19), Thundr-Dmg/Rchg(19), Thundr-Acc/Dmg/Rchg(21), Thundr-Acc/Dmg/EndRdx(27), Thundr-Dmg/EndRdx/Rchg(37)
Level 20: Arctic Fog -- DefBuff-I(A), LkGmblr-Rchg+(21), LkGmblr-Def/EndRdx(36)
Level 22: Flares -- Thundr-Acc/Dmg(A), Thundr-Dmg/EndRdx(23), Thundr-Dmg/Rchg(31), Thundr-Acc/Dmg/Rchg(33), Thundr-Acc/Dmg/EndRdx(34), Thundr-Dmg/EndRdx/Rchg(45)
Level 24: Ice Shield -- RedFtn-Def/EndRdx(A), LkGmblr-Rchg+(34)
Level 26: Glacial Shield -- RedFtn-Def/EndRdx(A), LkGmblr-Rchg+(37)
Level 28: Benumb -- Acc-I(A), RechRdx-I(37)
Level 30: Tough -- S'fstPrt-ResDam/Def+(A), RctvArm-ResDam/EndRdx(43), RctvArm-ResDam(45), RctvArm-ResDam/Rchg(48)
Level 32: Inferno -- Erad-Acc/Dmg/Rchg(A), Erad-Dmg/Rchg(33), Erad-Dmg(33)
Level 35: Sleet -- RechRdx-I(A), RechRdx-I(36), Achilles-ResDeb%(36)
Level 38: Heat Loss -- Efficacy-Acc/Rchg(A), RechRdx-I(39), RechRdx-I(39)
Level 41: Shark Skin -- RctvArm-ResDam/EndRdx(A), RctvArm-ResDam(42), RctvArm-ResDam/Rchg(42), RctvArm-ResDam/EndRdx/Rchg(42)
Level 44: Weave -- RedFtn-Def/EndRdx(A), RedFtn-Def/Rchg(46), RedFtn-EndRdx/Rchg(46), RedFtn-Def/EndRdx/Rchg(48), RedFtn-Def(50), RedFtn-EndRdx(50)
Level 47: Combat Jumping -- Zephyr-ResKB(A), LkGmblr-Rchg+(48), Zephyr-Travel(50)
Level 49: Hibernate -- RechRdx-I(A)
------------
Level 1: Brawl -- Empty(A)
Level 1: Sprint -- Empty(A)
Level 2: Rest -- Empty(A)
Level 1: Scourge
Level 4: Ninja Run
Level 2: Swift -- Empty(A)
Level 2: Hurdle -- Empty(A)
Level 2: Health -- Empty(A)
Level 2: Stamina -- EndMod-I(A), P'Shift-EndMod(29), P'Shift-End%(29)

| Copy & Paste this data into Mids' Hero Designer to view the build |
|-------------------------------------------------------------------|
|MxDz;1602;755;1510;HEX;|
|78DA9D54594F135114BE332D94AED352CB52A0B465296D61A051139707134012124|
|85062346A6C1A3BD0496AA72983D1377F8089892F3EE1F6EEBE25A051FC19C6171F|
|8DEB3FA867B9B4907973927EDF9D73CFF9CE39F7CCEDF28DF98010B74E09459BAB9|
|636368A7356A3B159B7AD46D7F2A65DB24DAB263C42888196BD78B6545B37CAFA82|
|D9308AB3106327DA7BB39B6B6BFA9C552D17E7AD6B668DE2238BB58AD1306AB6BEB|
|7F0AD5856555FAD1B4659A3E592512A1B8D8D8A590FD2FB82B95EB1CDDA7A606FB7|
|0E2FC9D375F3AADECEB5645C374B76A5542B2E431146E3661FD479147E1955C8A7D|
|921B6D020D4FB44EE074489874C8F88261F136D2BAD28219E28689A0021B636DDCA|
|2B167ACD426F88426F897ADE11BD075F97C2795DCF4821FC12A82052A89716E34F8|
|932CF89A65E1065214987ACB683937472924E4E12C80BD4E8E35C71CE9583288F2C|
|CDC3515D1CD575A0B43E764F83AF974B53BD7932F90E501EF4FCACA7F8F3EDBC191|
|181D0A0EC2A18E2AE7C44193F539028A73105881488D2E4696A71818D4E428A886C|
|34C263E9E6B174F3580EF158E23C96511ECB47908BCACAA309F68BD1A18E8489C64|
|1362665632CDBC3B209964DB26CEAC0B47720B657F6DBCBEDA462441F00FBE54E3F|
|EF8CF2CE27C001B933C03D8DE6895CD0ED1017E91AEA85C590C8252866324D343D4|
|CA443ADC3ACA00EFF54D12FF983E93BD12E7D12EC90E6F31F91B40B0E51F1191CC6|
|E8A36CAA6377543A00FE3E24555D424CC85226B8862CD790E51AB2292237949C976|
|3CDFBE824A7FC4C01A2E9205121C4A411F540942EA7A17FA5F4D33C8DC2177AFB06|
|FF263372EE335CD1A07BDFC56AC223961C961577EBA609852C8B6D9FA6370C174BA|
|EFFF3D90EECC979CFF8005711CE219C47B8807011E112C265842B084584E64E2B5A|
|3B86751D47388170122106F589DBE8E9C13BE4470820041142081A4218218A1047D|
|8F2B73AFA05C18AB2BFFFDF0ECB1F87E56FDBA22A493EECBB3486C17B44338E83CE|
|392C0587E588C372D861699FEC3FEEFE3D1C|
|-------------------------------------------------------------------|

| Copy & Paste this data into Mids' Hero Designer to view the build |
|-------------------------------------------------------------------|
|MxDz;1597;744;1488;HEX;|
|78DA9D53594F135114BE336D295DA7A594A585026529A530D0A889CB83092009092|
|42C1A8D1A9B860ED004DB665A127DF3079898F8E2136EEFEE5B021AC59F41FC03C6|
|F51F8C67B96D69E6CD49FA7D9DEF6CF79C7367F9D6BC5F883BE785A2CDEDE4ABD5D|
|C5CD934772BB5B2D9BEBC5BCBD78AE592700B21E20D3DB7962F6D19057DA1681AB9|
|5988A9259AB6D9DDCD4D7DAEBC53C8CD976F164B141F5E2C6D1BA651AAE9F53FDE9|
|57279475FAF184641A3BF4B46BE6098D5ED622540EF0BC5ADED5AB1B4E5AF5B2BF0|
|12BF50296EE8CD5ACBF90D03A05A33CCDB3D70C453F04BA9423E964BECA120D4874|
|4CE474489C74C4F88269F12ED2B8D28219E29288D4322562DA7F28613BDE544EF88|
|82EF89BA3E107D045F87ACEB784119863051528C3D274ABD249A7AC5F49A280D455|
|C32CAC545DAB8481B17F16780B2A2876BC5B8D60444B9E5D1DC1CD5CE51ED2D47EB|
|61F724F87AA8154BF56448F2B65006F2F9389FE2CB34EBA6441842031CEA0A04A9A|
|B909728E5630A104D684C7E2205A234CEE7D05604361A5A259ABE48945D239A84BA|
|61D97D9877D5C1BBEAE05D75F2AE62BCAB11DED567A81191ED4412EC1755704AC32|
|1A231481B9569A39CB68BD32638ED20A71D6AB9020710DB2D87D0CD3D0E45893E01|
|F64A4B2F5B46D8F205302E2DF118F534922172C008FAE585EAEF56F04587630DB0A|
|40EFC54511AFCC1F49DE890AE043B2479FEC3920EC12122BE82C3285D4A4B1DBDA7|
|52AF7C3F2455E0068ECB758D076918693E709AD7956E59D724AFCB0967CD709423C|
|3239CEA249A0E33F178BBC04F673F45FF46E5B34744C36099917398414BB26EE973|
|1EFBB02C78C4924D597136BE34A190B2D8F4B13CA1C687F5BFCFBEBF9ECEB3EA055|
|C47B8847019E10AC255846B08D7116E20E410AC8346B4761ACF7506E12CC2398428|
|9C4FDC454F377E433E043F42002188A0218410220831843D5FA3A35F10AC28C7FBF|
|F6D53FED894BF4D45550669FD7DF779E60F88666C839EB029599B72D2A69CB029CD|
|C9FE0339253C07|
|-------------------------------------------------------------------|

My fire/cold uses dark mastery and has these numbers which work out marvelously:

30.4% Melee defense
29.2% Ranged defense
29.8 AoE defnese

44.5% S/L resist
34.1% F/C resist
23.1 energy resist
17.3 Neg/Tox resist

99.9% of the teams I am on have me sitting way over the defense softcap to all 3 positions. If I'm ever not at the softcap I can pop a purple insp or two when needed. On smaller teams or when solo where defense buffs aren't present I still don't really take much damage.

It really depends alot on what you want to do with the toon, what kinds of teams you are usually on, if you're on large teams or small teams or solo, if the people you play with also play support alot or if you will find yourself solo supporting a team often, or if you just want to be completely independent of outside help, how aggressively you play, how willing you are to use insps, etc etc.

In general, I would never mix typed and positional defenses. There's just too much wasted overlap for it to be worth it. Either take the build with RES, or try to work one with AoE and/or Melee defense too (not necessarily softcapped, but within a small luck perhaps)