I changed my Nacra F18 for a Capricorn just before the UK Nationals. First impressions were that it was faster upwind
but pretty similar downwind, it is however much lighter to steer than the Nacra. The training day and first day of racing proper at the Nationals were fine but then the wind just kept picking up on each subsequent day and I found it very hard to sail downwind in conditions that, while challenging, I would have been happy with in the Nacra. Saying this, the fast teams on the Capricorns had no problems at all and so I would summize that the problems I had were down to a)technique + ability and b)setup. So while I pitchpoled my Cap more times that I want to remember I think this was more me than the boat, the others seemed fine - and it's worth noting that it wasn't just me going swimming, the eventual winner pitchpoled his Tiger.

TMG mentions the earlier qualifier in Pevensey when the wind reached 39knots - I don't think that James and Gillian capsized their Cap, but retired after their jib blew out.