Assuming equally skilled players, without insps, and pvp dueling builds... BS/Regen, no contest.
Without insps, Katana hasn't enough burst damage to defeat a properly-played Regen. Stacking DA on top on SR's defenses is nice, but the BSer can still hit easily with BU + FA, during Elude downtime.
It'll be hard to die for either of them if they are good, anyway. Even if they don't move, a duel without insps between those two scrappers can last for hours... possibly years if one or the two of them have Intimidate. 
My Katana/Regen has beaten a Broadsword/Regen on several occasions. The trick is to get a pure-melee opponent so that they don't try and kite you... Regen vs Regen duels DO tend to last for ages though.
So a Katana can often be damaging enough to kill another /Regen, but my bet's easily on the Broadsworder in the above example. Parry + Regen > DA + SR, and (as much as I hate to admit it) in PvP Broadsword > Regen.
If both are played properly, it would be a tie, no one would kill the other
Scrapper vs Scrapper is generally down to lucky crits more often than not ending in a draw
thePhilosopher Martial Arts/Regen/Fire Scrapper
theRegulator Empathy/Energy/Soul Defender
Total Inertia Ice Blast/Kinetics/Psy Corruptor
Total Inferno Ice Blast/Thermal/Leviathan Corruptor
Personally id put my money on the SR/Kat. You would have to engage, make the Regen use instant healing, then disngage. Run until that dropped, and then move in to kill. But, the /regen would probably disengage until IH recharged...
So it would be pretty dull tbh... 
SR would have (Can't remember the name, makes you run and recharge faster) though, so the running Regen would be caught up with a thrashed.
The better player
"Well, they found my diary today.
They were appropriately appalled
at the discovery of the eight victims
They're now putting it all together.
Women wrapped in silk
with one leg missing
Eight legs, one body, silk,
spider, brilliant!"
[ QUOTE ]
SR would have (Can't remember the name, makes you run and recharge faster) though, so the running Regen would be caught up with a thrashed.
[/ QUOTE ]
It's called quickness, and a regen would have to suck big time to die, same goes for the sr
Lucky crits from the regen could kill the SR. I guess the same would go the other way if they had an equall primary, but I cant see Katana doing the burst damage required to down a ragen..... but that's just me, am a documented katana hater
"Well, they found my diary today.
They were appropriately appalled
at the discovery of the eight victims
They're now putting it all together.
Women wrapped in silk
with one leg missing
Eight legs, one body, silk,
spider, brilliant!"
If the Devs dont nerf Focussed accuracy a bit ( ) No SR will beat Regen at arena. And if the SR pop Elude there is always a nice accolade called Geas ...
Speaking according to the "No inspirations" rule you mentioned.
Would the BS/Regen not have a slight advantage due to their attacks doing -def (particulary parry I believe). Whereas the kat/SR wouldn't have anything (within normal power ranges) that does -regen
Not sure how large an impact this would have though.
Not if the SR has aidself
As all self-respecting SRs do
"Well, they found my diary today.
They were appropriately appalled
at the discovery of the eight victims
They're now putting it all together.
Women wrapped in silk
with one leg missing
Eight legs, one body, silk,
spider, brilliant!"
But aid self isn't -regen!
Unless its changed remarkably since I last used it...
Nope, that's why they would always tie
Frankly I can see no way that the SR could win here, and at least two ways that the Regen could win.
Focussed Accuracy and Build Up properly slotted is about +64% ToHit. That's enough to punch through SR's +31% melee defense like it isn't there, plus one +23% DA buff and nearly half of the PvP -25% ToHit penalty.
Along with PvP accuracy slotting, the regen would have a big advantage even allowing for 'Aid Self'. The SR simply won't have any defence worth talking about unless they're running elude or stacked DA constantly.
That's not even considering the -defence from the Primary attacks, which will be -15% to -22.5% constantly. For Elude or stacked DA, the Regen could use the Geas the Kind ones accolade for a short buff to +ToHit.
I'd also bank on the SR running out of endurance before the Regen (either through spamming Aid Self or Elude's crash)... so unless the SR plays to kite and/or conserve endurance, they will wear themselves out.
Just to throw some numbers out there for consideration:
The regen will be hitting against about 2-9% defence constantly with (FA + Attack effects) vs (SR defence + PvP ToHit penalty). Build Up will counter the remainder of the defence, plus one instance of DA. Outside of Elude, it's therefore basically down to Broadsword spike damage versus "Aid Self".
Aid Self will recover about 500HP (at level 50, slotted) for a scrapper and it's up every 20-25 seconds. At level 50, a scrapper has about 1390HP (1670 HP with all +HP accolades).
At level 50, Broadsword's most damaging attacks are:
+ Headsplitter (480ish damage, slotted + Build Up)
+ Disembowel (360ish damage, slotted + Build Up)
+ Hack (300ish damage, slotted + Build Up)
You can just about fit these into one "Build Up" chain, 480+360+300 = 1140 damage, so it'd take a Critical Hit with Headsplitter (for 1620 total damage, 15% chance!) to kill a (non-fully-HP-accoladed) SR outright.
Ok very quick and simple this one, but interested to know your thought's and comments on this fight.
I want to know what do you think would win the battle in RV a Broadsword / Regen V Katana / Super Reflexes.
No Insperations would be allowed in the fight.
Thanks all