Pettneu is a pretty, quiet village about 6kms from St Anton on very frequent (typically every 15 mins) free skibus routes. We stayed at Camping Arlberg Feb/Mar 2017 right by the Wellness Centre (also very goof facility). Pettneu is not a place to go skiing, but with the whole Arlberg ski area (the largest in Austria) close by, it really is no hardship to catch the free bus to either Ost or West bus stops in St Anton. Pettneu has a few bars and restaurants and a reasonably priced supermarket. Coffee at Backer Reutz near the church is excellent.
St Anton is fairly lively at times and food is available quite late compared to other German/Austrian resorts in our experience. However, whilst lift system is very good, the pistes are poorly maintained and it is not uncommon for blue runs leading back to the town, particularly the rather inappropriately named Happy Valley & run 50, to be full of moguls. For beginners this must be intimidating. Shame on the St Anton pisteurs, given the amount they charge for lift passes!!
In conclusion, Pettneu is a great village to stay, but with easy access to St Anton, Lech & Zurs.