Welcome to mobileread
I have the Sony touch and also live in the UK so I will give you my own thoughts.
Some people may view the touchscreen as an expensive gimmick but I love being able to turn the pages using a quick swipe of the thumb and also I really love the dictionary feature where you just tap on a word for a definition. I don't use the notes much but has been handy for jotting things down which I think of as I'm reading - shopping to buy and mundane things normally!!! I really like this added feature.
There is a slight flicker when the page is turned, have to say I barely notice it and I'm a pretty quick reader. I think that is just the way the e-ink hardware works so I assume it would be like this for most ereaders and not just sony.
I got my Sony touch from whsmiths and the price was £219 which was the cheapest I could find anywhere on the Internet so I think I got a pretty good deal. I guess you do pay a little more for the Sony brand but when I compared this price to say something like the cool-er which was almost £200 - it was a no brainer for me.
If you don't think the touchscreen will be necessary then perhaps the sony pocket edition would be a better bet and, again, I found the bet price for that at whsmiths for £149.
Hope that helps.