This might be a little late, but personally right now I live with a non-ROTC roommate. I will be moving in with a ROTC roommate next year. Having a non-ROTC roommate was not a problem generally, but I found it quite difficult to put on dress uniforms in the dark because I didn't want to bother her early in the morning. Additionally, our sleeping schedules definitely clash -- sometimes she doesn't come home until 1 in the morning and I've got to be up at 5 for PT, but that's not to say conflicting sleep schedules is not something you won't encounter with another mid.
Most of the 4/C in my unit went for ROTC roommates, but I'm glad I gave a non-ROTC roommate a chance. She's nice, and I've met a bunch of non-ROTC friends through her. (Also, she's really good at shining shoes when she's bored.)
As always, it depends on the person you end up with for both cases, but as far as non-ROTC roommates go, it really boils down to how patient you are living with someone who may not understand the responsibilities you have towards your unit, and how considerate you're willing to be as far as things such as waking up earlier than them.