Question [Q] Can I switch to T-mobile simply by changing my SIM card?

I have a VZW Galaxy S3 that is rooted, running the latest SlimKat ROM (probably not important, but just in case). I have a T-mobile nano sim that I was thinking of activating for a month just to test out their service and see if I wanna switch.

Would it be as simple as activating the SIM card online and popping it in my phone? Is there anything else I need to do? Like maybe something with APNs?

Thanks!