We went to meet our daughter who was back packing around Central America for 6 months. We spent a couple of weeks ourselves, flying into Cancun then catching buses (both the express variety and the chicken buses) around Mexico & Belize.
It was all good, but according to Sian, Costa Rica, Nicaragua, Honduras, Guatemala Mexico and Cuba (where you stay in peoples houses) were all better. Quay Calker & Ambergris Quay are very americanised, Belize City is scary, Placencia is lovely and there are things to do in San Ignacio.
Most of the people were lovely, especially the guy who didn't speak English or Spanish, just Creole, and realised that we didn't know we were in for a 4 hour bus-ride (we thought the $2 was just getting us from the border in Chetumal to Corazol, 10 miles away, not to Belize city) so he hopped off at the next stop and got us 2 big bottles of water. The man who got on, waving his machette around at Orange Walk was a bit scary, but the locals said it was OK "Es loco!" and he got off at the next stop to shout at some policemen he'd spotted.
If you like corn tortillas, you'll be fine with the food.