Tbh the N80 is a great phone, has some smashing features on it but its extremely poorly implemented. Not only that its quite a thick phone, like a tiny brick. I did have one when they first came out but i wasnt in the slightest impressed with the phone. The slider mechanism left a lot to be desired for and i found it a slow and extremely cumbersome phone to get on with. Also no auto focus on the camera is another silly idea they decided to implement so pics come out pretty crap really, even at the highest settings.
After i sent mine back i then went for the SE W810i, have had it for 3 months and i havent looked back at all. Although it doesnt have as many features as the n80 but it does what it says on the tin and imho the pics on w810i are a lot more clearer and sharper than the n80 and thats from a 2mp camera where the n80 has a 3mp camera. The w810i may not have built in WIFI, which incidentally first attracted me to the n80 but i should be getting the SE P990i soon so im not too fussed at the moment.
In all honesty i would go for the w810i over the n80, its smaller and lighter and funnily enough has replaced my video ipod for my mp3's. I dont think ill ever go back to Nokia now, ive had 2 of them 6680 and n80 and i was majorly disappointed with both whereas every SE phone ive had...well ive not had any complaints about them.