I had a Nokia N70 before I got my N95, and the N95 is definitely must faster (less "laggy") but still not perfect. The quality is fine, and I can't think of many features it doesn't have. If you want a good, solid, reliable phone, the N95 is the best thing I've ever seen from Nokia, and I place Nokia at the top of the list for mobiles. As for something you can hack -- I don't know. I gather there are options for the…
Bonus points that I use Windows dev platforms on a regular basis, so it would be fairly trivial for me to deploy on a windows mobile phone.
Still bouncing around the ideas I'm seeing.