Yes. I do it all the time. The only difference between doing it on a non Touchwiz phone compared with a Touchwiz phone is that the phone sees it as a handsfree device so will answer on the Gear by default, even if you hit the answer button on the phone. You just need to tap the little icon next to the 'End Call' button on the Gear though and it will route the call back to the handset. You can also tap the bluetooth icon on the dialer and switch the source to earpiece or speakerphone. Bit of an annoyance but not a particular problem.
I'm running a TW based ROM and I can't even get it to connect. Just hangs at connecting to gear at the setup... Did you do a clean setup or did your settings carry over when you updated?