I suppose i have the same problem. ive got my second nexus here because I love the phone but my first one was randomly rebooting, making "fax" noises on calls, and had generally poor reception.
I just activated the second one last night and when I switch it to CDMA I get no connectivity.
Currently i have a weak 4G signal, -114dBu/26asu. When I switch over to CDMA (3G) it is -93dBu/2asu, however under these conditions it will not connect to the internet. (it will connect to the web using 4g) and 4G drains the battery so bad its not practical to use it exclusively. my first Galaxy nexus would connect to the web on 3g from my house. Fortunately i have wifi that I can connect to when necessary in my home, but I'd like the phone to work as it should.
I chose to exchange the first phone because of the poor reception and a few other issues. I will work with this one for a few more days to see if I can make it work. Perhaps the rumored OTA update will remedy some of this?
Alright, Ill follow up on my previous post on this issue: I got my replacement Gnex and this was the phone I was having this issue with. Once I left my house and started traveling around, I saw an improvement as it started to switch out between 3G & 4G.
My guess is that it needed to "learn" the cell signals or something?
BTW, I posted this issue at first as I had only had the replacement phone at my home where I am on the fringe of 4g. The first Gnex I had had a weak 3 g signal and had the random reboot problem. With the new one I have almost forgot what the boot up animation looks like!