I have the M and the Maxx. I just got the M and must say it is a MUCH better phone than the Maxx.
-The CPU and OS are leaps above the Maxx. The phone is so smooth and frankly up to date. The circles widget is an excellent clock and is finally a worthy replacement for HTC's Sense Clock. The OS itself has a lot of things on it that just make the experience better, like the ability to add or subtract new home screens - up to 7, or the true ICS experience without the hard keys. While the Maxx may get updated to the same operating system it will just never be as smooth.
- Battery life seems just about as good as the Maxx. I must admit I shut off 4G on both. While I'm in a 4G area, I don't see the need to use it. So I save a little more batter life that way. Definitely all day battery with both.
- I don't have tiny hands, but the Maxx is slightly too big to use comfortably with one. I find while the screens are nearly the same size, that I'm able to one-hand the M easily.
- The M also has NFC which means I can do payments from my phone, and send pictures by just touching phones to others that have it like my sister's Galaxy S3.
- The cameras seem the same. Neither is great. HTC has it all over Motorola in terms of camera quality.
-The only thing thats truly disappointing is that I can't use data and voice at the same time (like I can with my HTC Thunderbolt). I thought they would have figured this out by now, but they haven't.
The Maxx it was a plus minus game comparing it with the Thunderbolt.... big plus on the battery which lead me to buy that instead of the HTC Rezound.
But hands down, the RAZR M is the best phone I've ever owned.