I think it's utterly cool. I've always loved
Quentin, but maybe, just maybe, now that you've brought the name to my attention, I love
Quintilian more.
I'd never heard of the historical
Quintilian until just now when I looked him up, and I don't think most people have, so I wouldn't find it very important.
Most little used Latin male names make me think of a guy who is smart and sexy.
I think it's usable! Yes! Use it!