Yeah, I used to do Trials comp about 15 years ago.
I doubt any rego’able bike will be a true trials comp bike, there’s just no way they’d pass one of the modern comp bikes.
They are very very light and very slow, 60Km/h is all you will ever get out of one, max! Very close ratio 6 speed box. They only carry about 3L of fuel so they wont go far either.
They are purpose built and would be fun if you have somewhere to ride it or plan on doing comp. but their small brakes would overheat easily on trails.
Horses for courses really.
Look here; http://trials.com.au/