I flew on TACA from Houston to Belize and was very happy with them. It was a new plane, the agents were extremely friendly (I asked one if he had a pen so I could fill out my customs form and go to hand it back, he says "no sir, please keep it in case you need to write anything else down). They kept my ginger ale filled, asked if I needed anything a few times and the business class was the same as UA Domestic first, but a little more comfortable

The TACA counter line was a bit long, however they were VERY helpful once I showed my 1P card