I will be forever grateful to my Kindle Keyboard 3G as it reintroduced me into the world of reading. Therefore, I was really looking forward to receiving the upgraded Kindle Touch. There are, however, some really disappointing features that have left me feeling somewhat let down by the product. The most annoying one is the search engine. Whereas the keyboard version lets you look things up with wikipedia and google directly from the book that you are reading, the touch version only offers wikipedia as a search tool. Also, the keyboard version is designed so you can use both hands when going backwards and forwards when reading a book, but the touch version is set up so you can only go back a page with your left hand. If you want to go the end of a chapter to see how much you have left to read and then travel back to the previous point that you were reading from, you only need to press two buttons with the keyboard version but the touch takes three actions (not a big deal I know but annoying when it is and upgrade). Finally there is the cover with a built in light. Although it is not strictly a part of the Kindle Touch, it is an essential addition. For some unknown reason they have designed cover with a light that shines directly into your face!
If none of these things bother you, then it is definitely worth it as an upgrade. It is more compact, the touch screen is intuitive and the dictionary format is much more attractive. For me, however, it wasn't worth it so I sent it back.