The GNex has a sub-standard antenna. When released, there were complaints about poor signal, and Samsung/Google tried to hide this by modifying the signal strength meter. However, there were repeated reviews and tests performed that showed comparable competitor phones had better signal strength under the same conditions. In other words, they would put a GNex alongside two or three other similar phones and the GNex would show considerably lower signal strength (dBm).
This was the sole reason I didn't buy it and instead went for the Droid RAZR. RF performance should be the most important aspect of a phone -- it is, after all, a phone.
So my recommendation is not to get the GNex unless you are willing to put up with a higher incidence of dropped calls, inability to make calls, and possibly faster battery depletion.
As a matter of personal opinion, I thought the build quality was not great for a phone that retailed for $299 at release. For a "Nexus" device, it felt a bit cheap.