I'm not an expert on the software and I do not know how it exactly runs.
Though I can tell you from my experience that it does not edit or change the boot sector in any way that I've seen. It really helps boost performance of a 'Warm' boot or a 'Restart Windows' the most. As for turning it on out of no where, I wouldn't know since my PC runs 24/7 and is built to be that way.
For Truecrypt, that I have notice it only speeds up it up and I have had no problems with it at all in relation to the software.
I believe the Max VeloSSD contest is over, however when you sign up for an account on http://www.elitebytes.com/ you can request a trail version of the Max VeloSSD for around 6 days. Please do post your benchmarks somewhere on before and after using the software, mine was such a difference I almost pee'd myself.
Also one last thing, I'd suggest using the trial for Max VeloSSD since it is not the full software just yet. Plus you PC might not be able to handle everything perfectly and you do not want to waste a couple hours trying to get your product key reset like me. Something notable would be also that if you buy a 'Professional' license from EliteBytes you can either use it on VeloSSD OR Max VeloSSD which I may be wrong.
From what I've gather it made my general hard drives run around 230% faster and better, and around 40% better than the standard VeloSSD. That is just a rough estimate from what I have gathered on all of it, DO NOT TAKE any of this as actual fact from the company. I AM NOT associated with them in any way, but I sure as heck wish I was for the great software. I have it on my personal pc + my server now and haven't had a single problem that wasn't my fault. (Hehe, programmer humor since we break stuff to figure how it works.)
Good luck and tell me if you need any help with things.