Hmm...dunno...little skinny subs are good...but you kinda worry you might break them, y'know?
Being larger not only provides a bigger target but it provides so much more to be bound and waxed and clamped and so on.
The most important thing is what's inside your head - the attitude you take to yourself and especially to submission and to D/s and all the other things that go into that. If a 'Dom' can't pick up on that cerebral stuff and interact with you as a submissive (as opposed to a piece of eye candy) then why would you bother with them anyway.
Have fun.
J