I bought an N95 8GB a few days ago, impressive piece of kit.
My m8 at work bought a Viewty from Dialaphone a couple of months ago & has had no end of problems with it.
I used to swear by the Sony Ericsson models as the battery life was incredible, but they lacked the functionality of the N95.
The things that swung the N95 over the K850i for me were:
5MP Camera
Built in GPS (I also loaded Garmin, TomTom, & Google Maps)
WiFi (can piggy-back onto unprotected networks)
MP3 Player with 3.5 standard jack.
etc, etc, etc
The N95 is much more than a phone, It's a mini computer, so battery life will be on the low side, but I suspect that you won't be far away from a PC/Power Point/Car Adapter, so charging it back up shouldn't be a problem.