Ive been with esprit 10 different times. So I guess I think they're ok!
I've been to most of their French resorts. I'd avoid val disere if you've got beginners though I do love it there, ditto chamonix.
Tignes has a reputation for been a bit tough but I learnt to ski there and it was fine. Some of their chalets in all resorts but particular tignes can be away from the main ski lifts, school meeting point. I remember at tignes having a ten minute walk every morning with heavy skis, not good.
Courchevel is my favourite resort in the world. I've not been to their new chalet hotel there but a friend has and said its great. It's a good location as well.
I've been to their chalet hotel at la plagne and I liked la plagne but didn't like the hotel. Very swish, pool, etc but too many guests for the dining room. So dinner was in two sittings and was rushed. Not a nice atmosphere.
La rosiere is very nice. Small resort and very good for beginners. Experts can ski over into Italy on the lift pass for more runs.
Plan peisey is amazing. Lovely chalets, good location. Nice resort.
I've never stayed in les arcs but have skied there and it's nice skiing.
I think they've got chalets in les gets now as well and again les gets a nice resort, no idea what the chalets are like.
They use evolution 2 or esf for their ski school and always get instructors with good English. Kids are in a class where it's just other esprit kids. They get taken to lessons by snow rangers and picked up. Child care has always been fine.