Hellgate Unit F was fantastic!
My only worry going in was the reliability of the shuttle service, but it turned out to be outstanding. The shuttle would usually arrive withing 5 minutes of our phone call, and it takes less than 5 minutes to get to either Alta or Snowbird from Hellgate. Drop-offs for us were at the top of Chickadee at Snowbird and at the bottom of Collins at Alta (but I think you can also get dropped at Sunnyside). At the end-of-day busy times it might take ~15 minutes to arrive sometimes, but I was thrilled that we could shuttle home for lunch and get back to the slopes quickly after a mid-day break.
People have mentioned the stairs, so I will clarify. Unit F is right by the office. From the shuttle drop-off, everyone at Hellgate has to descend two short flights of covered stairs to get to the main entrance where there is an office and ski lockers. Unit F and several others have their doors here. When you enter Unit F, you immediately climb stairs up 1 floor to get to a big open room where you can shed gear. From there, you enter the condo that shows up in the pictures. So, in addition to the ski locker by the office, there is also a huge room where you can store all of your gear (jackets, bibs, helmets) outside of the main unit. That was great for us, and the stairs were not an issue at all.
As far as the skiing, even in a VERY low-snow 2020-2021 early season trip for the week of New Years, most everything was open. Getting back and forth from Alta to Snowbird through Mineral Basin was easy. The snow was good. Lines were much shorter at Snowbird (except for the Mineral Basin Express lift). Both live up to their reputation of being advanced resorts, but my (very experienced) 10-year-old daughter was still able to go just about everywhere. An intermediate skier at Alta/Bird might find there is not enough to ski for a week... and some of the blues are pretty steep.
Finally, the views from this place are amazing. We could watch adventurous skiers/boarders climb Mt. Superior every morning and leave tracks in some pretty remarkable lines. The dining room window is huge and has the best views I have ever had from a ski condo.
Whole process was very easy. Garage parking was nice. Getting into town for forgotten groceries wasn't bad (20 min each way).
It's probably best categorized as "rustic" and definitely has some quirks, but it was perfect for us and we will definitely try to come back if it's available for a future trip.