I agree on use of the Stealth boy to help the sneak skill in a mulitplayer environment. Sneak would reduce amount of noise made, and how effective your cloaking field is. Maybe suppressor perks for those with high sneak. Assassination/Mr. Sandman like perks would be nice too.
Players with 0-20 sneak my find it only renders them opaque, still visible, but if standing off in the distance, would be enough to go unnoticed.
21-40 may get a more active camouflage from it allowing them to blend in with surroundings easier.
41-60 begin to fade out, but noticeably blurring in and out of sight, especially during heavy movement.
61-80 would be well hidden, with the predator-like wavey aura being their give away.
81-99 being completely hidden, medium to heavy movement being the only disturbance in their cloaking field.
100 - Perfect cloaking, unhindered by pace of movement during sneak mode.
Attacking would remove the cloaking field and disengage sneak. You would need to wait a few seconds while your stealth boy recalibrates and remain unharmed in order to get back into stealth. Any damage done to you will knock your stealth boy offline. Concussive effects from heavy explosions (even if unharmed), EMPs, pulse grenades will remove your cloak as well.
...How does that sound
?