Oh good point, maybe next time I have spare cash and go to Play'n'trade.

The GB Boys don't pitch bend properly, they're a bit faster and out of tune, and from what I understand the wav channel is also a bit weird sometimes.
So no, they aren't really that great for LSDJ.
And you can find an original Gameboy on eBay, craigslist, or a locally owned retro game store for cheaper anyway.

Well. IIRC there are other problems. Such as pitch-bend not working as intended and such things. I do not think that LSDJ translates 1:1 with a GB Boy as with a Game Boy.
I think I read that somewhere. I don't really remember where. Maybe it wasn't for these units...

Sit tight, someone with better knowledge is sure to come by. : ]

EDIT:
I found what I was referring to. But it was said under the GB boy colour units. I have no idea if the vanilla GB Boy has the same problems, but something tells me "why shouldn't it?". But again: I could be mistaken, and I hope I am.

Well other than it being a little faster is that gameboy fine?

I think the comments* below vote against it.

* The comments on kitsch-bent site.

Are theses gameboys http://store.kitsch-bent.com/product/gb-boy suitable for lsdj? Someone in the comments section said the processor's a bit faster, is that a huge issue? I already own a gba sp (the first kind I think, let's you turn the backlit screen on or off). I've been looking around for an original gameboy but all the ones I've found so far on amazon have an issue or two like dead pixels