Simple really.
Noisy in town. If you don't intend to party the night away stay away from the centre.
Sunny valley. Freeze thaw is common but you have Val Thorens which is high and Courcheval which is north facing so you are pretty much guaranteed reasonable skiing.
Samey? I just don't know what that means. Meribel runs are no more 'samey' than any other resort and I have skied about 50 in my 39 years of skiing. Off-piste is accessible and plentiful as are groomed and non groomed runs. Maybe I have an impression of Meribel as a more blue/easy red resort but there is plenty of challenging skiing in the3 valleys if you want it. The couloirs off Saluire are a hoot.
Is Meribel a favourite: no. It has too many rude French, is too dominated by Brits, and is too expensive for the mediocre standards. At least Val d'Isere delivers better for the cost; in truth Austria, Italy and Switzerland have, in the round, more to offer.