Energy blast is my favorite set in the game. I know it isn't the greatest, but the KB is fun. I tend to only slot the -KB IOs in the range AoEs (no need for single target and why would you want to ruin the KB on nova???). The one thing I would change would be change it from a chance to KB to KB. (Do any other secondary effects other than KB occur at random?) And please Please PLEASE, don't add a gimmick to energy blast!
Random thoughts for the other sets
Fire - great set
Ice - great set
Rad - eh...
Dark - never got it very high, may try it again someday
Beam - not enough aoe
water - too gimmicky
electricity - never got into it
AR - new updates make it better, aim woulda been nice
archery - never tried it
dual pistol - never tried it because of stupid animations
seismic - couldnt get into it. Also, its meteorite, not meteor...
sonic - never tried it
storm blast - great new set, lot of fun
New set I would love to see is my reimagined assault rifle, aka Battle Rifle