In reply to Eagle River:
Oright then, seeing as I have nowt else to do...
There are two issues here: 1) could climbers brought up as trad climbers easily convert to being top level sport climbers- the answer to that is obviously no; and 2) could climbers brought up on clipping bolts easily convert to 'tearing up' british trad.
The second question seems almost as obvious as the first to me. We've seen experienced trad climbers, who are stronger than the UK's top trad climbers come over and do pretty well. We've also seen our own top sport climber (who was brought up on trad) match current levels and hint at being able to better them.
Outside of the 'pembroke phenomenon' we've seen little evidence that strong boulderers from elsewhere, or top-level sport climbers could easily convert to new levels of trad climbing.
There are different ways to look at it; first off, let's get the conversion tables out: The hardest Ondra has onsighted is F8c+. Let's assume that he can't climb at this level whilst placing nuts- say F8b+ (which is pretty generous I feel. What grade is that going to get? It would be mighty impressive, but I'm not sure it would class as 'tearing it up'- like onsighting an E11 or something.
As far as I'm aware, his hardest onsights were also long, sustained, fairly easy to read routes, that relied on limestone pockets and crimps- Not 20 metre brutal/blind cracks- like the majority of very well-protected British H9s. So there's a difference in style there to think about too. I don't know how much Grit/volcanic stuff europeans get out on either- I suspect not a lot- apart from granite.
Then there is the issue of gear. If you've been brought up placing nuts and friends, then you think nothing of falling onto a couple of bomber pieces, but after chatting to a lot of sport climbers-turned alpinists in austria, there is a fair bit of angst at even the most tame falls onto the best gear. The idea that running it out 7 metres above a bolt is just the same as running it out on something like Rhapsody, with wires you fiddled in with little if no experience of placing gear whilst pumped, is daft. Whatever you say, it takes a while to learn to really trust gear, which is what you need to be able to do, if you want to onsight anywhere near your limit.
Having said this. If he spent 6 months cruising a few E7s/E8s, I'm sure ondra could 'tear it up', but he's not going to just pop over from ceuse and onsight Rhapsody.