jimbo's jet
The key to being happy in the Centre to East of Europe is through knowing what to expect from each base, as you allude to.
Wizz have 11 bases currently (12th in Wroclaw announced today). Some bases have waiting lists, such as: PRG, BUD, WAW. Others are seemingly less popular, perhaps BBU (Bucharest Baneasa) being one, mainly due to the cost of rental there.
Katowice is the biggest base. It is home to some of the Fleet Management, who are approachable and professional. The city is pretty grim, but the flying is varied and there are always lots of comings and goings.
There are a number of factors that help with pay, but the main is the number of sectors you fly. Bases with short sectors seem to provide better pay packets.
Cost of living varies, but is cheaper than home. You will need to pay tax to someone though. It's not a tax dodging place.
The airline is growing and is well run. I like it.
But the best advice I can give is to make sure your base has plentiful connections back to the UK.