I've had mine for a week now. This is a HUGE upgrade from my iPhone 3G! I am still in the process of learning Android, since I have not had a chance to really sit down and tinker, but the basics seem pretty easy to figure out. It is simply a beautifully designed device. It looks and feels better than just about any other Android phone out there. I do not understand cnet.com's review stating that the design is "uninspiring".
As far as performance goes, obviously anything is going to be an upgrade given that I'm coming from a very outdated phone, so I can't compare it to anything from the last year or so. However, it has performed VERY fast and smooth, with no noticible lag. Voice call quality is just fine, and I have not had a problem with earpiece buzzing although I do get a slight rattle, which seems to be normal with most smart phones, as I have read it is related to the camera auto-focus. I also have not had any problem with a yellow tint on the screen as others have mentioned. I really like the notification system and ease with which I can pull down the "quick settings". Battery life hasn't been great, but seems to be getting better with a few full charge cycles.
There are a couple things I do not like, however. First, the speaker placement on the back of the unit means it is difficult to hear the phone's ringtones and notification alarms, unless the volume is turned all the way up. It would be nice if they could keep the speaker from being obstructed. I wish the screen would turn on and show text messages when they come in. I would also like to be able to reply to a text message from the lock screen instead of having to open the sms app. I did notice a few apps in the play store that can achieve this (mainly Sms Popup) and will be looking in to those. I had to jailbreak my iPhone to do this, but found it very valuable. I would also like it if the notification LED flashed more frequently, but again, I understand there are apps for this (Light Flow) that I will have to look in to. I also wish Google offered a way of backing up the entire phone with my Google account instead of just syncing my calendar and contacts, I would be interested in learning to root the device at some point. However, I feel it is best to spend some time learning how to use Android more fully first. As customizable as it is, I may not need to root, but learning how to would be interesting.
Overall, I'm very glad I purchased the Nexus 4. It is exactly what I wanted, and although I would have liked to have LTE, I will probably be ok without it for now. It took me several weeks to find a phone I liked after I decided not to go with the iPhone 5 and was pretty disappointed with nearly every Android phone out there. I'm very glad I waited it out, instead of compromising with something else.