I don't think a person has to be a twig for it to be OK really. Sure, I was a twig in high school playing tennis (5'2" 95lbs). Not so much a twig now though.
Obviously one wouldn't want to go from normal tennis shoes to minimalist immediately, just like you wouldn't want to be a runner in regular shoes then go to running barefoot immediately. It takes a long time for the muscles that haven't been used much to build back up and be able to handle something like that.
I already went through the "oh my god my calf muscles and feet are killing me" phase when I first started wearing these types of shoes regularly for physical activities. It lasted for a while, then I really started to notice a huge difference in the strength of my calf muscles as well as my ankles and knees no longer bothering me. The difference was amazing... I really wish I had tried this back in high school. My tennis bag back then was like a mobile pharmacy of pain meds, knee braces, and stuff like that.
Really it's just whatever works well for the particular person though. If tennis shoes are working well for you, then great! I'm not trying to convince anyone to switch... I'm just trying to find something that will work well for me and not put me back to the path of knee and ankle problems again like what plagued me through most of my life. I kind of like having the muscles down there able to actually pull their weight now and not just relying on the shoes to handle all that.
I've still got a couple months to find something that'll work and that will hold up on the courts. Too much snow on the ground to play tennis yet out here.
I do think that my KSOs probably won't work too well. They are a little more "sloppy" on the foot and not too tight. That's why I was interested in the KomodoSports... Maybe they'll put those out in a 38 eventually. If not it sounds like there are some other alternatives out there which might work. Thanks again for the info and discussion on this