I've found that in the market they all have their pros and cons and that the differences are variable depending upon the circumstance, but the camera certainly isn't the feature to be bragged about on this phone. I've found that one of the ports of the Nexus 4 camera produces the best results most consistantly on my handset. I've also often wondered if my handset got the short end of the stick with the camera it has since a lot of other people are happy with the quality they get out of their RAZR HD, though I'm coming from a Galaxy S 2 which takes wonderful shots in comparison to some of the phones out now despite it now being an old phone model. Its the one thing I really miss about the S2.
On a tangent, I played around with a Galaxy S 4 today and did a bit of camera testing. Single shot stuff. I didn't find that it was all that much better than the S3 or S2 for taking single snapshots. The anti-shake setting worked but not quite as well as on the previous devices, for example. That was really all I could test though, since they always have great lighting when you're looking at phones. Quality is quality, but I'm not convinced 13 megapixels is better than 8 the way Samsung implemented 8 on the previous devices. To be fair though, I had it at 9.5 megapixels. 13 restricts you to a 4:3 shot.
I'll have to try out Camera MX now