can't comment on white room but have been with joyriders where i rode my ht. i'd take my bouncer next time, just because i have one now, and didn't then, but would still go on a ht if that's all i had. i want to go back next year. i walked some stuff, of course. i don't know about you, but if you're not riding some stuff at the edge of your ability, then you're not pushing yourself, and really, at the end of a week's riding, i want to come away better than i was before – that won't happen if you're in your comfort zone all the time.
i went to verbier this year ( bikeverbier.com ), and walked probably more, but was in a group of riders where i was probably middle of the row, if not towards the bottom end, and they have to cater for everyone, so it was inevitable that i would do more walking. also, in these places, you're generally doing much more descending in the course of a morning, than you would in a full day's riding in the uk, so if you walk 4 times in a day, it's probably equivalent to walking once here.
TBH i think it's the nature of the game. you will always be challenged. when presented with it, either get off and walk it, or ride it, but just make sure you enjoy yourself. there's no point beating yourself up about this 5hit!