I see your point. But I never claimed it would be capable of overstuffing an extra size because of the 10% - I merely said that it couldn't hurt to have a little more space for the same dimensions. Also: Smaller looking rig with the same amount canopy in it.
Another very valid point. I am planning on freeflying, but if I choose to jump a used rig in the 190 canopy size, I will probably sell this rig before I start freeflying for real. If I buy new, this will of course have to be taken into consideration. The Danish National Freefly Team is from my club and they all jump Vectors though, now that I think about it. But most people in my skydive community are very Vector-biased.
Also a good point. Money is no issue as such, but things still has to make sense and not be retarded. My problem right now is that I'm 197 cm tall and weigh about 97 kg, which makes most used rigs unfit for my freakish body. Furthermore, I need to jump bigger canopies than the average rookie skydiver because of it. So I can't wait around forever for a usable used rig to show up - though it might be the best thing to do, jump it for a good many jumps and then buy a shinny new rig when I know more about what I want and what I can safely fly and land.