I also found that there is DPX available in both 165 and 185 gr. I guess the lighter the bullet the less recoil???
Maybe, maybe not. The lighter bullet is probably traveling at higher velocity, which could offset any recoil reduction gained by the lighter bullet weight (depending on how much faster it is).
Of course, if they are traveling the same speed or even close, the lighter bullet should give less recoil.
I've not compared those two in DPX form, but CorBon's standard JHPs in 165 and 185 felt about the same to me.
Many can often tell a difference in recoil between a light/fast bullet and a heavy/slow bullet in the same round. One is not neccesarily "heavier" than the other, but it just feels different.
As an example, I'll compare the "stiff", but not +P, CCI 230 Gold Dot and the +P CorBon 185. To me, the 185 CorBon feels sharper, or recoils "faster", but the actual recoil effect on my control is about the same. The recoil is just delivered differently.
But back to original EFMJ vs PowRBall:
While I would much rather get the gun fixed to feed what I really wanted, I would choose PowRBall...all things being equal such as reliability, no big point of impact shifts, huge accuracy drop-offs, etc.
In most tests I've seen, I haven't been impressed with EFMJ's penetration. I was really impressed with Mr Camp's 38 Super CorBon ammo test, where even with the high velocity (as pistols go) the PowRBall actually penetrated quite well.
I must admit that I have some 9mm 124 +P EFMJ and it is very accurate stuff. I keep a stash of it around for shooting groups. That, and CorBon 115 JHP, are my accuracy "control" loads in 9mm.