The N800 is cluncketiclunk regarding the UI.
The N9 is actually nice (except the lagging and poor to no customization possibilities). As a tablet Swipe would work much better than the N800. That is not the problem. The problem is the N9 is not competitive against the Androids or iPhones. It is not even competitive against Symbian Belle. Belle is good, relatively speaking, and the N8 (a two year old phone) is outselling the N9, and so does the E6. You can say that people don't want WP (Lumia), but there is one thing they don't want more, and that's the N9. Windows CE has never been a complete OS out of the box. It has been a set of libraries and source for anyone to build a OS to their likings. As such it has been extremely popular for all sorts of devices, GPS in particular. There still is very few if any "better" alternative out there for screen-centric devices. Android would probably? work, except it would suck the batteries dry within minutes. WP is built on a solid core, that's for sure, and it can be seen from the smoothness of the UI. If (correction - when) the prices of Lumia 800/900 come down, I will probably get one. Right now I see no value there for me.