The E7 appears to have more software bugs than the N8, which is pretty stable. The leaked Symbian Belle is available for the N8. I've been using it, and it's pretty good. In some ways, I prefer it to Meego-Harmattan.

The Symbian browser is quite poor, though the Belle version is an improvement. Install Opera Mobile for the best experience.

The only things that would attract me to the E7 are the larger screen and HWKB, though the HWKB is similar to that on the N950, which I have found to be a bit cumbersome compared to the N900. The larger size means that your thumbs need to travel further for each keypress, which reduces typing speed in my experience.