I have had believe it or not 3 N73's ... the silver, the brown, and the ME. I still have the ME but am going to sell it off because of Creakiness and instability. All three of my n73's with firmware upgrades have consistently given me "sim registration failed" errors few times a day. Not only that, the camera freezes up on these phones as well. I really tried to love the n73 and actually i still do love the phone, but i just cannot use it as an everyday phone. Maybe weekender.
But seriously, i know the n80 may not be the tightest slider made, but do not bring in design when comparing the 2... the n73 by far is one of the worst phones i've ever owned when it comes to design and build quality. Not saying the n80 is great, just saying the n73 design has to be one of the worst, with the 4 buttons surrounding hte keypad that cant hold itself up against the housing to keep itself from creaking, to the camera lid thats almost as long as the entire back of the phone which obviously over time gets loose and rattles. Not sure how they came up with these ideas, but if they could somehow fix these issues, the n73 would be the bomb for sure.
Honestly, im not sure about keeping the n80ie either, i have to play with it more, but i will say this. If you want the better cam, go with the n73, if you want a "cooler/hip" look go with the n73 (ME!), if you want wifi and a more professioinal looking phone go with the n80ie, if you want a more stable phone go with the n80ie, if you want an incredibly sharp screen go with the n80.
I havent noticed anything horrible about the n80ie battery life yet. I guess maybe cause i use wifi only when im at home where there is a charger handy. Otherwise when using gsm mode and wlan scanning is off, the phone is normal on battery life.
I'll report back if theres anything i notice.