While I have a love-hate relationship with tequila, as I believe we all do, this is a rockin' deal for that first hour. I do believe this is actually in violation of the law (selling alcohol under the cost to purchase - Handle of JCE ~ $34/40 shots), but hey, who needs the law?
The first time I went was in January (coinciding with a friend's birthday) and it wasn't crowded at all. However, I also stopped in for Febuary 5th at around 5:15pm and it took 30 minutes in line to get a drink (I promptly left after said drink).
Next month's Cinco de Montho will probably be equally or more crowded, as student's will be concluding their first week back from Spring Break, and needing to unwind.