Is this a good deal? Help me out please

Mind me asking what you didn't like about the S3? Some of those same qualities you didn't like in the SG3, may be in the Nexus. As for relevance, just because the SG3 has better hardware doesn't mean it will be anymore relevant than the Nexus, a phone line that's been known to get direct Google support. Hardware is indeed part of the phone, but it's the software that plays majority of the role and that's where the Nexus comes ahead.

That being said, in my opinion, that's a good deal. Of course I'm partial to the Nexus, but you get a very good phone in the Nexus as well. The only downside between the two is that the SG3 uses better radios and has a better battery life out of the box. If you're into ROMs and doing some real customizing, the Nexus is the device to have, if that's not your type of thing you may want to look at another phone.

 

The nexus is smaller than the s3 though a bit thicker iirc (the width of the s3 makes up for it though). The Nexus does feel a bit sturdier as it's a bit thicker and heavier, and the plastic doesn't feel cheap. Not sure what you are talking about when it comes to spots, never noticed any.

The way I see it, if the Nexus is still going strong after almost a year I don't see why the s3 can't follow the same path. It's got the better hardware overall and is a great phone. It may not be supported directly from Google, but if you're like me or any other flash-o-holic then the dev community definitely has your back.

Before anyone says I'm partial to the Nexus(which I am), I did own an S3 for a week just for fun. Nexus was just the phone for me so switched back and stuck to it. Hardware wise I felt it's the perfect package and even for my big hands a bigger phone was just harder to use with one hand. Software wise, I feel it's just miles ahead of any other phone, especially with support from the dev community.