I am pretty happy with my 800 - the one thing that I would change would be to make the display easier to read - under some conditions, the contrast is much lower than I would like for it to be.
The unit seems to mostly have been designed around racing, and I use it for touring and recreational social rides - it would be nice to have features like being able to find things like restaurants, bathrooms, motels which are along the route - they can find ones that are close to your location, but it has no way of figuring deviation from a planned route. Other features, such as virtual partner are completely useless to me.
There are software fixes that would be nice - their route calculation algorithm for bicycles sucks, it could be much better, but I haven't upgraded the firmware in my unit for over 6 mos, so it can't be that bad...