I ditched my Bionic for this one.
Reasons for the switch:
1. I never could get used to the pentile screen...would cause eye strain from time to time when scrolling through web pages and reading e-mail. The new screen is an immense improvement despite not being as good in direct sunlight.
2. The headphone audio quality for Bionic SUCKS SUCKS SUCKS....worst audio from any device I have ever owned. The GS3 audio is superb and now I can stream my google play music library without getting annoyed.
3. Battery life when using LTE was absolutely terrible. I FTP into my office to download large files when I'm on the go and my battery just dies so fast...I can kill my battery and the replacement battery just like that. I'm always hunting for wifi connections. It also made it so I couldn't stream music from google play (even though i didn't even want to because the headphone audio quality sucks).
4. The Bionic is thicker, heavier and "chunkier". After quickly adjusting to the GS3's weight and dimensions, I sort of forgot about my Bionic. I grabbed for my Bionic this morning and couldn't believe how much heavier and chunkier it was. As an example: when the Bionic was in my jean pocket (I wear slim-straights), I definitely noticed it was there and it would bulge out a little bit. I would never attempt to wear skinny jeans with a Bionic. But....I DO NOT EVEN NOTICE THE GS3 IN MY JEAN POCKET. A couple times already, I've had to check to make sure it was even there. For such a big phone, that's just awesome. The thickness and weight really makes a difference.
5. The "Don't call it motoblur" UI is a joke...nothing more than eye candy with no really useful additional features. It's a useless memory hog imo....and it often stands in the way of apps I would prefer to use from the market. I've messed around with some leaked ICS builds on the Bionic and it has improved dramatically...but still not as nice as Samsungs UI.
6. I like turtles.