Being an OG EVO owner from day one, I can say that I love the 3D, faster speed, and larger memory. Really thrilled at how good my Blu-ray 3D movies look in 3D, and YouTube 3D videos, too, but just hate the crappy speaker downgrade (should have been two EVO speakers in stereo). Dislike the relocated side position for the USB port. Sadly missing the kickstand.
The phone has rebooted several times or crashed in the past two days since getting it, with no obvious reason why. Had to pull the battery at least four times. Most annoying is to discover upon reboot that the apps stored on the SD card that had icons on the desktop need to have their icons recopied to the desktop to replace the annoying Android icon placeholders. At least the apps themselves still work, but I've already had to recreate my desktop screens (which are quite full) twice. Not fun, not even a little bit. No, I have not installed any additional task killer apps.
Still like the phone, but it's not exactly stable yet. Keep checking for another OTA update that fixes some of this unpredictability, but not holding my breath 'til then, either.
The biggest issue, though, has got to be the overwhelmingly time consuming transition/transfer/resetup/configuration going from the EVO to the EVO 3D. I'm not rooting my phone, so I'm not using Titanium Backup, and I haven't found any reliable tools to copy over all my app config data. Other than trying and failing with My Backup Pro, which copied some relatively unimportant things like text messages and call logs but actually *deleted* my old bookmarks, there doesn't seem to be a good and quick method. At least I found the Angry Birds save game backup and restore utility, LOL. I've spent the past two days reinstalling and configuring all my apps on the new phone, and I'm finally basically done. I may just sob when I drop this thing someday, but honestly, there needs to be a better way, as literally spending days reconfiguring a multimedia device such as this are days you'll never get back.