I see no reason to get the GS3 with the Note 2 available. Played with a N2 for a while yesterday at a Verizon store and loved the S Pen and it actually didn't feel too big in my hand. Not sure how it is for everyday use being so big, but if you're leaning Samsung you are doing yourself a disservice by not checking out the N2.
That said, I hate Touchwiz and hardware buttons, and I'm happy with my Maxx HD, although I was happier before the JB upgrade.
After installing Nova Launcher yesterday, I'm happier with my Maxx HD. I liked it before, but now I
really like it. The phone scrolls through screens noticeably smoother now. The softkeys now really shine as a feature because I removed the redundant on-screen google bar but can still access Google Search/Voice Seach/Google Now with swipe-up-from-Home. Now I'm glad I have a phone with softkeys. I also made some other tweaks that I like with the customization options Nova has.
However, without Moto's launcher you do have to work around the lack of the Circles widget and the lack of the swipe-to-the-left for quick settings. I liked Moto's quick settings, but I'm okay with using an alternative to that because the lag in swiping to the left was annoying. I'm using Widgetsoid to add quick settings to the notifications pull-down instead. There is an advantage to that, in that you can put whatever quick settings you want in there, instead of what Moto picked.
Overall I feel that with Nova, the phone is smoother and more tailored to me. It took me a while to figure out what to replace Moto's widget and quick settings with so that I'm satisfied with the look and functionality, but I think the end result is a better phone for me. IMO, Maxx HD + Noval Launcher > GS3 because of the battery life and softkeys.