I've been several times w/my work crew - service is friendly & fast, everything is always clean, lunch specials are cheap ($6-$8, cheaper than Panera now) and I love the raspberry-mango margs.
Cozumel has your typical Mexican-American fare: burritos, enchiladas, taco salads, etc. The salsa is fresh and although I've had a stale chip here and there, overall the quality is good for the price. The waiters are usually very good-humored and they never hassle us about splitting up the check. Three and a half stars!