First of all...what's with the "which phone is more slippery" debate? Am I the only one who uses a case anymore?
As far as the OPs question...there is no significant advantage with the Galaxy S III over the Galaxy Nexus. Benchmarks do not tell the story so if you are looking at quadrant scores and think there is a significant performance jump...you are mistaken. Forget Jelly Bean for a second because the Galaxy S III will get that eventually. But there is no way in hell it will get Key Lime Pie (or whatever the next version is called). The Nexus S is getting JB but the rest of the original Galaxy S series is never going to get ICS...why?
Well, it's very simple. Phone manufacturers are into selling new devices...not upgrading old ones. That's why the Nexus devices are the best to buy. I don't care what anyone says, the Galaxy S III is only marginally better when it comes to hardware specs. It's a big loser when it comes to software. Vibrant owners are hoping for a port of some kind...Nexus S owners are waiting for their guaranteed JB update! I didn't buy the Nexus because it was a Samsung device...I bought it because it was a Google device
...what can I say...I'm a purist.
What fragmentation problem??? THIS is "our" iPhone and I say the Galaxy Nexus is still the best Android phone on the market when you factor everything in. One phone per year...upgraded to the latest software even when it is not the latest Nexus device...bootloader wide open so Google can watch what developers can do with it for both apps and mods. What does the Galaxy S III bring to compete with that? I now believe most other Android phones are mostly irrelevant. Think about it. What SIGNIFICANT phones have come out since the Nexus S launch:
1) HTC Thunderbolt because it was the first phone to have 4G.
2) Samsung Galaxy Nexus
3) Motorola Droid Razor Max because it was the first phone to be slim and really deliver on battery life.
That's it folks. The Galaxy Nexus is slightly better than the Galaxy S II and slightly worse than the S III when it comes to hardware so I really don't see them as significant phones...except for the fact they sold a ton of them. What else? The Bionic, Razr (non maxx version), Rezound, all Sony phones, Atrix HD, etc...all have the spotlight and then quickly go away. The S III and One X are new and shiny so they are at the top of the "experts" lists right now. Will they be at the top of the list in 3 months? The S II came to AT&T and then the Skyrocket followed right after it. Give the customers one new hardware feature and piss off the customers who bought the S II with 3G. Bionic owners know that feeling all too well don't they? Nexus owners will always have something to look forward to (as long as the hardware can handle it).
Sure...the hacking community may get JB or KLP to non Nexus devices eventually if the manufacturers do not. The camera may or may not work...random reboots, GPS failing to lock, and apps not running properly will be commonplace. I've been there several times and don't see myself going back.
I do not want to switch carriers but after finally having a taste of a Nexus device...I will ditch Verizon if they don't have the next one. I have two upgrades coming up this year and will not be using them. If there is a Nexus device...with a plan that makes sense...I'll stay.
The Galaxy S III is a bad ass device so don't think I'm saying that it is not. But it is not a Nexus device and that kills it for me. I've already recommended the S III to several people...but those people don't know what version of Android it is running nor do they care. People that buy the Nexus don't usually ask which phone to buy...at least that is my impression.
Sorry for the long post/rant