Salsa, you're right, I've been using Aerobase V, as well as No Slackers and Uphill Grind. For about the last month I did NS and UG once a week, separated by at least a day, and ABV twice a week. More or less.

I actually have 3 other DVDs from the interval 5-pack that I haven't cracked open yet - Suffer-o-ama, Muscle Breakdown, & the Sprinting Machine. I'll get to them eventually.