*points to sign saying "Do Not Poke Da Refs"*
If you want the Vest itself to be Subtle, that needs to be on the Device power itself, not 'in' the powers the Device grants.
There are two fairly minor changes I'd like to see on the char sheet. First is to list the Save DCs for his attacks. Something like "Punch, +2 melee, Toughness DC 20 [damage]" and "Tranq Gun, +3 Range, Fort DC 13 [stun]". This helps the Refs out quite a bit when running combats.
Second (more a pet peeve of mine) is to alphabetize & use proper terminology for things, specifically the effects from the Monkey Wrangler Vest. I'd like to see it look a bit more like this:
Device 8 (hard to lose, Monkey Wrangler Vest): Enhanced Attack 3, Enhanced Defense 3, Enhanced Feats 4 (Accurate Attack, Improved Initiative 2, Power Attack), Flight 3, Force Field 3, Super-Strength 7.
As I've said before, this is going to be a very tough character to play, but if you're up for it, I'll look forward to seeing him in action.