In terms of location Les Constellations is fantastic. There is underground parking under the apartments (shared with a number of other residences) so you do not need to drag your luggage outdoors.
It is true ski in - ski out, with a short run down to the nearest lift.
There is a small supermarket almost opposite the front door for essentials.
It is a short walk down paths and stairs to the village centre.
Belle Plagne is a nice small centre with a reasonable selection of eateries and bars.
Given my experience of other resorts this one did not feel extortionate, with pizzas and pasta dishes widely available in the 10 - 12€ category.
With regard to the apartment, we booked a 4 person studio, but were upgraded to a 6/7 person apartment, which was nice.
It comprised of 2 bunk beds in the entrance hall, 2 sofa beds in the lounge and a double bedroom upstairs. There was a toilet and shower room downstairs and a toilet and bathroom upstairs.
As there was only 2 of us we had plenty of room, however, if there were 6 adults I think it would be cramped, hence the lower rating for comfort.
The bunk beds were quite short and a tall adult may struggle.
The small kitchenette had an electric hob, combination microwave oven, dishwasher and fridge. All very clean.