I currently am looking at switching to Sprint and am looking at which phone to get. It seems to be between the S3 and the Optimus G. I went in to the store and played with the 2 phones, and loved the look/feel of the G much more than the S3. I preferred the G's design, it has a better size, and it feels sturdier. However it seems that the G is not really 'catching on' despite it's great specs. On Amazon there are very few cases/accessories for it, even sprint's own website doesn't have a lot of accessories for it. However Otterbox built a case for it, so they obviously think it will still catch on. They seem to only build cases for popular phones.
I think one thing holding me back is LG's reputation. They haven't always built the best quality phones or backed their phones up with support/updates. I've also read things about the phone overheating to the point that the screen automatically dims itself from 100% to 65% or something like that.
So for me I really want to love this phone, but I just don't know if I can pull the trigger over the S3 yet....