I have recently returned from a short break at St Luc and can thoroughly recommend it. The scenery is fantastic and the village is traditional and picturesque - the perfect antidote to larger, purpose built resorts lacking in charm or personality.
The skiing in St Luc is good for a short break - for a longer break you might want to hire a car to visit other resorts in the valley that are covered by the lift pass. The pistes were wonderfully empty and lift queues did not exist. It was great to ski on empty pistes with stunning views of the Alps - again a contrast to larger resorts. The skiing is best suited to intermediates, although I am sure experts would enjoy plenty of fresh powder due to the lack of volume of people.
Transfer from Geneva airport is great - two hours on the train, followed by a short hop on the post bus.
Go if you like uncrowded pistes, great scenery, traditional alpine villages. Don't go if you like lots of apres-ski options and nightlife, large skiing areas and drag lifts.