In reply to paul mitchell:
It all depends on what one means by 'physical limit'. I'd go one further say probably no one climbs at their physical limit.
The first reason is that its hard to find a route precisely at your physical limit (neither too easy nor too hard).
The second problem is that to climb at one's physical limit implies making absolutely no mistakes at all, perfect timing, perfect pace, using all your muscles in perfect coordination to negate any wasted effort. To have any chance of performing such a feat would require many days or weeks of practice on the route first.
Thirdly I'd say that 'physical limits' in climbing are at least partly mental limits anyway.
Defined that way I'd certainly go along with the statement no one solos at their physical limit.
People can look very sketchy when soloing but I think that might often be more mental than anything: climbing badly because panic sets in. Put the same person on a top rope and see how they climb the route then.
Post edited at 20:43