l2a is definately a better park and there is way more of a summer ski and fun scene there. it is more crowded as a result but i think i would be a better call for sure. as for ease of access, l2a isn't really any harder to get to than tignes from lyon. you could get a bus direct to either or a train then bus to either. tignes is a train to bourg then a bus, l2a is a train to grenoble then a bus. i would imagine there would be mo buses from grenoble to l2a than bourg to tignes.