The main difference: hot yoga is usually a vinyasa flow that varies each time you attend a class. It's like regular vinyasa with an extra element. Bikram follows the same sequence each time, is slightly hotter, and has more breaks. I'm not a regular Bikram practitioner, but it sounds like practicing often will align with most of your goals, and if you need a little variety, you can always do a hot yoga class.
P.S. The "new age" spiritual stuff, when presented correctly, is actually based on ancient scripture and tradition. I hope people aren't out there teaching naked yoga Scientology!

I tried it a few years ago and liked it. I am determined to get back into it, but so many other types of hot yoga have sprung up since then. Have any of you compared Bikram with other forms of hot yoga? My goals are to sweat, stretch, increase my strength and lose a little fat. I am not interested in new-age spiritual yoga, no offense to anyone. I'll probably use Bikram studios in Tenleytown and Bethesda, if that makes any difference.
Thanks for any advice.