I guess I should put my thoughts in while I still have time.
First a little about what I've played while testing. I made up 4 different characters with Sonic and I have to say I like the set alot. 3 these characters have been defenders.
Sonic/Sonic
Rad/Sonic
Kinetic/Sonic
Each of these builds as a Defender lends itself to very different play styles and team compositions.
I've heard alot of chatter on the boards about Sonic Blast doing too much damage, I'd have to say I disagree. When compared to the damage that a controller does to a held character (using an Illusion/Trick Archery Controller for comparison), a defender stacks up right in line if not slight below the damage per attack. The defenders have more attacks that do actual damage then a controller does, but that is true for all defender secondaries. Along the same lines, people have posted that the DR debuff is too big. Again, I have to disagree. Using my Rad/Sonic Defender with both Hasten and Accelerate Metabolism, I could only get about a 33-35% boost in the damage I did based on the DR debuff. And that included the +DMG boost from AccMet. Can a DR debuff actually take you to negative DR? If not, then I would not worry too much about stacking from multiple players. If DR debuffs can take you to a negative, then putting a cap on max DR debuff would seem the best way to protect. Just like there is a cap on heroes DR buffs.
One of the other topics people have been posting about was the END cost of Sonic. I can say from experience that once you get past the first 2 powers in the Sonic Blast set, END is a definitely factor in the set. If AccMet was down, I was running out of END by then end of each encounter with mobs of 4 even level minions. The END was especially heinous for AoE/Cone attacks like Howl.
The big point I can agree with most posters on is the sound effects. Shriek and Screem are ok, but Howl really needs some work. I've been tempted to break out my Midi keyboard and send in some wave files to use.
As some others posted I'd also like to see the visual effects come from the mouth., and the idea of pulling 1 hand up to the mouth for Shreik and 2 hands for Scream sounds really cool.
Here is what I've put together for stats for the first 4 powers for Defenders...
Shreik: Ranged, Minor DMG(Smashing/Energy), Foe -Res(All) [END Cost 5]
Scream: Ranged, Moderate DoT(Smashing/Energy), Foe -Res(All) [END Cost 8]
Howl: Ranged (Cone), Minor DMG(Smashing/Energy), Foe -Res(All) [END Cost 12]
Shockwave: Ranged (Cone), Minor DMG(Smashing/Energy), Foe Knockback [END Cost 14]
Note that my stats do not agree with what the game list. Howl, Shreik & Shockwave all have the same pretty much the same base damage. Howl says it is Moderate, but I think not. Additionally, Shreik, Scream and Howl say they only do Smashing damage, but they are Smashing/Energy. Only Shockwave's description is 100% accurate.
Hopefully we will see a text correction in the next test release. I'd like to see the powers stay as they are.
Well, that was my 2 influence worth on Sonic Blast. I look forward to the dev's feedback.