I've got a 2011 petrol hatch owned from new and now at 40k. It's a fantastic motor, solid as a rock and much cheaper than the equivalent Golf GTI. The boot is massive, average mpg from new is around 37.5 as I do a lot of motorway miles and I've only had a couple of warranty claims.
It's just had a new clutch/flywheel/slave cyclinder due to a cylinder fault that caused the clutch to wear out, and a new wheel bearing has just been fitted as it was rumbling.
As far as I'm aware there's nothing specific to look out for, just the usual bodywork damage and service history. Parts are easily obtained as they're shared across the VAG group and there are loads of Audi/VW/Skoda/SEAT independents about who can work on them if you want to avoid main dealers.
I'd recommend one to anyone. If you're after a diesel, and have the cash, the limited edition 'Black' from a year or so ago had nice grey wheels, full leather and some extra toys.