I switched from my 3gs to the SGS3 month ago. I also did it because of the screen. The SGS3 screen is beautiful and responsive and so easy to watch/read. I've found some replacements for apps that I was used to on IOS and I have learned to live with the shorter battery life (it is shorter than my 3GS even with Juice Defender in operation). I now have a Philips dock - which was the only android compatible dock in the local shopping centre. My BT car set up still functions though my charger requires external cables rather than a neat wired in cradle.
Unfortunately I have not found any suitable on-ear headphones. (I cannot use the in-ear or earbud style) IOS users can pick from a huge range with inline remotes, mics, volume control, open or closed back, big cans or neat foldables. In the meantime I cannot find one set with an inline remote that will control the volume on my phone. I finally found some philips on-ear headphones with a working mic but the volume control does not work. The app just brings up Google search and others reviewing the app in the play store have noted the same problem.
So despite all the customizations available to me, I cannot get what I need for a phone that is supposedly the biggest selling phone in the world.
If anyone has a suggestions for over-the-ear headphones with inline remote, I would be very grateful to hear them.