After a few days with the S3, and a large amount of time running it along side the MAXX, I can now confidently say that
my original post in this thread was spot-on. If I were the type of person who keeps a phone for the long haul of a two year contract, I completely believe that the MAXX is a better device. The reception and battery life are enough to knock out any advantages the S3 might have for the vast majority of people. I'll just add a few additional thoughts from some real world use of the S3 versus the MAXX.
The reception is better than I expected. Having had a terrible experience with the Galaxy Nexus on the reception front (I went through four brand new ones, and all of them continuously dropped voice and data), and having had poor reception on the Charge, Stratosphere, and Fascinate, I was really worried about the reception on the S3. But the S3 has the best reception of any Verizon Samsung Android phone that I've used. I have yet to notice it dropping a signal. That said, the reception definitely falls below that of the MAXX, the Rezound, and the iPhone 4S. The S3 also seems to opt for 3G in weak 4G areas more often than any LTE phone I've had on Verizon, including the Galaxy Nexus.
I live on the edge of a 4G area, so 4G comes and goes from time to time. With the MAXX and the Rezound, I'd maintain a 4G connection about 70% of the time while in the house. With the Nexus, when it could hold a signal, I'd be on 4G around 50% percent of the time while in the house. With the S3, I've only been on 4G twice while at home, and both of those times I was on the far edge of the property away from the house. I've yet to grab a 4G signal while in the house. Out of curiosity, I forced the S3 into LTE only mode while in the house. It grabbed a hold of a LTE signal with the reception clocking in at -109dbm. The MAXX would pull LTE around -95dbm while in the house, and the Rezound would be a little weaker than that. The S3 connects to LTE just fine in areas with moderate to strong signal, but it seems like it's sticking with 3G in areas of weak 4G. At least it's holding a steady signal though, unlike the Galaxy Nexus which couldn't hold 4G, 3G, or 1X.
Battery life is pretty much on par with most current LTE devices at Verizon (clearly except for the MAXX). I'd say there's a slight improvement from the Galaxy Nexus, but it's not huge. With moderate usage and proper settings, you can get through a day with the S3. But you'll definitely need to charge each night. Power users will need a spare battery.
The S3 is the snappiest, most fluid phone I've ever used. I didn't think there was much room for improvement from how smooth the MAXX is, but there's definitely a noticeable bump in speed on the S3 in pretty much everything. I've yet to experience any lag. Along with the slight uptick in the processor speed, the 2GB of ram definitely seem to be helping more than I thought it would. But is the performance boost alone enough to switch from the MAXX? No way. It's not that big of a jump.
The screen is great. I'm glad Samsung opted not to go for on-screen buttons so that we can have full use of the 4.8" screen at all times. With the Galaxy Nexus, the dedicated on-screen buttons took the usable area of the screen from 4.6" to 4.3" 99% of the time. Since the RAZR HD will have on-screen buttons, I'm hoping Motorola goes with at least a 4.6" screen to keep the usable area the same as on the MAXX. But it sure will be tough stepping back down from the 4.8" of Super AMOLED 720p goodness that the S3 is packing.
The camera on the S3 is fantastic. It's better than I expected it to be. It really puts the MAXX to shame in this department. I travel a lot, and I often don't have a dedicated camera with me, so I use my phone for a fair amount of photography. I'd say the S3 is a slight step above the iPhone 4S, which was had the best camera of any phone I had used until now. If someone takes a lot of pictures, the things you have to give up from the MAXX might just be worth it.
Overall, I'm far more impressed with the S3 than I thought I would be. The snappiness of the device has probably impressed me the most along with the camera. But even though it's proving to be better than I anticipated, I still think the MAXX is the better all around device for most people. The battery life and reception of the MAXX alone trump all of the other advantages that the S3 has in my book. If I wasn't constantly switching phones, I'd stick with the MAXX. Since I plan on going straight for the RAZR HD and the rumored 1080p HTC as soon as they drop, I think I'm going to bid a fond farewell to the MAXX and let the S3 hold me over. But for most folks out there, I'd say stick with the MAXX. More so than pretty much any smartphone I've had, the MAXX does just about everything right.