Yeah, the problem with my brother's boots wasn't the heat (they heated ok), it just didn't last.
Personally, I think a tight fit (albeit one that doesn't compromise circulation) is crucial in a ski boot. I still haven't gotten over my racing days rule of thumb (we're only talking HS racing here, from just a **cough** couple **cough** years ago, poser that I am

) that your ski boots should be a size smaller (at least) than your street shoe. So for me there isn't a lot of extra room, even for a credit card.
I don't think they are poser equipment......mainly beacuse I doubt too many really good technical skiers are using the things (no judgement of those that DO use them intended 8) ). I suppose they are nice if you need them, but I've never needed them.....not even on those days at Whiteface when the mercury doesn't climb above 0 (farenheit).