i've only got pretty simple needs
That phrase makes me shudder. Hardware and software is so good these days that "Jo Punter's" simple needs are often much more than they first thought.
playing music and films
...then you'll wonder if you can stream your music and films to your hi-fi/TV like you saw once on that telly advert, and it looked dead simple then. Next thing you'll be wondering if you can use it to view your photos on. Oh, and it'd be good if you could do a bit of photo editing too. Why are your photos not showing where they were taken like you saw on that other advert? It's only a simple need. That long train journey? Maybe a few books/games would be good...
Sorry, being a bit cheeky, but the point is that you may find that when you realise you can do more than just surf the 'net and watch a few films, you may regret getting the more limited option. I think App support is the biggest factor in choosing a tablet.