I would definitely say that when I see/hear/read people using text-speak, it causes me to make snap judgements. The thing with me, though, is that I may make a judgement but I never give much weight to it. We're all wrong at times.
As for ages, I'd say that the younger generation these days (10-19) tend to enjoy the improper look of the words and the speed used to communicate with them. It's almost like they don't appreciate real english? (or conversations for that matter)
Either way, if I decide to sound like a fluff, I just whip out the zOMg liek u no wut i r seyin? pl0x dun tell n e 1 kkthxbai!!!!
Just like a tire-iron, it serves it's purpose yet other people find more ways to use it than intended.