There are great places to go in Gressoney. Buy the new edition of Polvera Rosa (just google it). It has good descriptions and great photos to show the routes.
You can do a lot without guides. Lots of offpiste easy to access. It tends to get windy and the sun can be hard on the snow, so powder is sometimes hard to find. Luckily there are good areas with trees where the snow is always better.
No queing at lifts and very few beginners in the area.
No nightlife - the valley is really basic and feels relatively untouched by ski tourism.
Alagna is great too but I have found better snow always in Gressoney and Champoluc.
Can't say about guides and choppers. We've found plenty by ourselves. If you want to go higher up, you might want guides unless you're experienced alpinists.
Great area with plenty of opportunities overall.
