I'll vouch for Clipz; back when I played on Azbok's Q2Jump server and then later in one of the jump-based mods he was pretty high up in the rankings. I'll bet he's one of the better jumpers in this mod based on a purely technical standpoint.
However the whole jump map thing lost its appeal to me pretty fast, once I got past the initial basics. I'd rather spend my time perfecting easier dp jumps so that I can do them at high accuracy during matches, getting better lines down on maps or finding some new jumps.
A hard jump would be on castle1 at the backdoor going from that single barrel onto the banner.
Ive done it like 5 times.
I've got a good demo of that
almost burning you in the last match the two of us had together
Lately I've been trying to work that into a line from middle or high(water ladder) exit. If I can get it down I'll see if I can post a demo.