A while back I bought a TM Desert Eagle AEP.
It's range, blowback, and otherwise poor functionality is identical to that of my clear walmart Crosman AEP.
.20s will fall sharply after roughly 5 meters. I found the .12s I've used in my Crosman P22 work great. Of course it doesn't go very straight--and I'm fairly sure you wouldn't feel the plink through a vest.
Save your money, don't buy an AEP--They suck. My Desert Eagle's hop-up is not adjustable. .20 go straight down, .12s are anti-aircraft rounds.