I've stayed at the Cliff a few times with my family... in fact, we'll be there next week.
All the restaurants are decent, if somewhat inconsistent. The Lodge Bistrot is maybe my favorite of the group, and we'll dine there one night this trip, but I've yet to eat at the Steak Pit. I think we're trying it for the first time on Wednesday.
I've had a good meal at SeventyOne, but also a disappointing one. It's basically bar/diner food. The Wildflower pizza is, well... I'm from North Jersey and spend a lot of time in Italy, so when I'm traveling my expectations for pizza are really low anyway. Ha! It's not too bad. We'll hit it at least one time.
The Aerie is more expensive than the others, so it depends on your budget, but I don't feel it's worth it. Personally, our plan usually involves destroying ourselves during the day to the point that come evening, we'll take anything that's hot and provides sustenance for the following day. That is also why we shuttle it up there. We go there to ski, and don't mind being sequestered for a few days. Last year on a trip to Soli/Brighton my son and I had a car, and frankly it was a pain to drive up and down each night for dinner. But there it was a bit more important since they don't have the same number of dining options, plus it was late in the season.
I'll be staying at the GMD for the first time in February, solo, so looking forward to seeing how they do it. This trip we'll split our days, between resorts, but ski Alta more as we prefer it.