my fam came out to visit me this past winter, i have 2 younger sisters who are intermediate skiers at best, and my parents are the same.
they liked solitude and brighton the best because of the lack of people at the tude and the ease of meeting up at the bottom (like someone up there said) at brighton.
however, solitude has absolutely no park to speak of, and brighton's is the subject of much debate as for the quality.
on a pow day lcc is ill, but the bird and alta can be very intimidating for a family of intermediate skiers, which could make your day shitty due to all the bitching and moaning.
bcc can be nearly as awesome on a powder day. solitude has great terrain in a lot of places and almost no one on the hill, brighton has fantastic slackcountry and is easy to meet up with the fam who takes the easy runs.
the only thing i don't like about the canyons is the runout on cat tracks to get back to the lift from some of the better runs outside of the park (and the price, but if mom and dad are footing the bill it's no biggie).
are you staying in pc or down in the valley? idk much about pc vacationing, but there are a bunch of rental houses at the base of lcc that give you access to both canyons very easily.
late feb- late march/early april should be a perfect time to come here, good snowpack, can be sunny or puking, i would stay away from holiday weekends if you can though, it can get busy.
hope that helps.