Buy a blackberry playbook. Currently the 64GB (yes 64GB) version has plummeted in price. I bought one for £129! The OS is nice - they seem to have borrowed a lot of swipe gestures from Meego.

Plus it will get BB10 - which means porting Qt Apps to it should be relatively straight forward.

I would definitely not recommend it at £500 - but at £129 it's an absolute steal. Rock solid build quality, top quality speakers, 1080p front and back video recording (front 3MP back is 5MP). Can run android apps on it, browser is quick, plays youtube HD stuff fine (no need for an app - although it comes with an app).

Everything is good value at the right price.