Don, have you played a Brainer? If not, why not?
In the games I've played in and run so far, one Brainer took the glove, one didn't. Both had/have functional but really weird relationships with and connections to the other PCs. Your basic premise, that playing a Brainer allows the player to disconnect, rings false to me - from what I've seen, playing a Brainer means getting inside some weird skin and digging in the dark places, usually with fantastic play results. Sure, they may be a step or two sideways from the reality the rest of the PCs experience, but not so much as to make it impossible to relate to them. So I disagree with your polling question.
One of the great things about the splat books is that people pick what they are drawn to play. If an MC was assigning splats, then sure, I'd expect players to disconnect all over the place, and not just with Brainers.
And as to gear, the pain wave projector is more practical and diverse than the violation gloves. Show me a Battlerbabe, or Gunlugger, or heck, any PC that doesn't want a reusable hand-grenade!