Personal review
I've had the nexus one for just over a month now. I have a contract with 3 and have signed up for their £5 a month internet service. I've found some good points and bad points about the nexus one.
Bad points:
The four buttons at the bottom. I've had trouble with these as they are not part of the screen, which is very nice and sensitive, they react differently. I've often found myself pressing them more than twice until it's actually reacted to the press.
Software glitches: I'm not sure if this is isolated to version 2.1 but occasionally I would have reset the handset as any reaction with the screen will send me to home. I always get the haptic feedback as well in these instances so they might be related to the four buttons again.
Battery life: This is to be expected from smart phones but the first few days I had it it ran out even during the night. I use my phone as an alarm and had a few days of getting up late because the phone died just by being on standby. I've since resolved this by downloading an app that can switch off some services that might drain the battery during the night and I get about 2 days out of it without charging and heavy use.
Good Points
Sync: The first thing I did when I booted the phone up was to check whether my google contacts were synced or not. They were all there and I entered a new contact via gmail on another computer, then used voice recognition to call the contact on the phone and it was there instantly. Very impressive!!
Mulit-tasking: to be able to have services running in the background I personally think is an absolute must for smart phones. To be able to have skype logged in constantly is great and I don't know how "other" smart phone users cope without it.
Speed: The nexus one is so fast and nippy. This is the first thing that people notice about the device. It's fantastic.
One last good point, and to summarise, is the apps. Even though the market isn't as large there are tons of other apks (android's install packages) out there. I've come across some great apps that resolved a lot of the bad points that I haven't mentioned.
All in all the hardware design has some flaws as mentioned but the software will improve as time goes on. Hopefully there will be a perfect design for the nexus two. :-)