RTS is good if you get customized coaching, guided programming is hit and miss. Either way, Mike T seems to like pushing volume to the absolute limit, so keep that in mind. I hear good things about TSA, I know a military guy who is with them and he also gets a discount since he is in the army. But from what I hear, most of the training is submaximal volume work (like 80%x3x6 sets for example) which some people don't like since you don't see weekly progress, but it definitely works. JTS sounds OK, they have some good lifters too, but again you are better off going for the customized option.
I hear 3dmj is good too, they (Eric Helms) do Bryce Lewis' (TSA owner) programming, you can look into that as well. In the end, it comes down to what style of training appeals to you and what you can afford.