I'm one of the other thirds of ChrisL's holiday planning so pitching in now... TL;DR version is that I loved White Room and I'm finding it hard to be convinced to go elsewhere! But for various reasons it suits Chris less well than it suits me and we're trying to find something that suits us both well.
For me, they had 3 strengths... Mostly, the riding was perfect for me. Always something happening under your wheels. Some stuff that I need to stop and look at, lots that challenged me, very hard work to go quick and well. Chasing Yvan was a joy. But I know it's not the only place to find that sort of thing. In the UK I love to ride innerleithen enduro and dh trails on my little bike and that's what it reminded me of most, only with more rocks and more dust.
2nd was the uplifts- it's not that I can't climb, we did a week with A Quick Release with proper mountains and no uplifts. It's just that I can climb in Scotland, but it's not so easy to get a chairlift! That's a big draw and if I'm going to pedal far, it's got to be seriously worthwhile.
3rd, the whole package was good- great food and people, good accomodation. I mean, I don't really see a weakness in that from my point of view. Very little nightlife, but I'm old and I'm there to ride not to dance to euro-pop
So it's a big ask really! Bike Verbier come to mind mostly because of the outrageously good feedback they get from everyone that's been.