Thanks for the responses! But I’m now in a position to answer my own question, and will do so in case it’s of use to others.
Last week, our kids (6-year-old skier and 9-year-old snowboarder) took two half-day lessons at Big Sky and two full-day lessons at Moonlight Basin. They liked all of their instructors very much and had a great time both places. They started the week skiing/boarding only greens comfortably, and ended with considerable confidence on blues. That said, we noticed a few differences between the snowsports schools:
BIG SKY
Pros: Kids really liked the terrain here (especially Mr. K and the natural half-pipe). Reservations are not needed (indeed--not accepted), and kids are not turned away.
Cons: In our experience, class sizes tended to be larger--6 or so kids per teacher--than at Moonlight.
MOONLIGHT:
Pros: Small class size. Classes tended to be 3 kids max, and sometimes only 1. Our experience was that, for half of each of the full-day classes, both children effectively had private lessons (at a group lesson price!). As a consequence, we thought they learned more skills/progressed faster at Moonlight than at Big Sky.
Cons: Advance reservations are recommended. We were turned away two days because all classes were full.
A couple of other notes:
- If you want to put kids in school at Moonlight and ski Big Sky, you can get complementary single-use tickets for the Six Shooter lift (actually, you’ll need 2 – one for dropoff and one for pickup), either from the Moonlight ski school or from the regular ticket counter.
- If you have beginning skiers/snowboarders that are attracted by terrain parks, there is a nice easy one to learn on along the bottom half of the Pony Express lift. This lift (and the Iron Horse lift) and shared between the two resorts, so you can access it with either lift ticket.
- My husband and I had an excellent private lesson at Big Sky with an instructor named Chris Wilson. We wanted to work on moguls, and he provided an ideal balance of very clear guidance on technique, some useful drills, skiing, and showing us some interesting terrain we might not have found on our own.