John, you actually get less motion blur with interlaced than with progressive. BUT 60P is definitely useful/essential for flying birds. Are you getting blur because you're de-iterlacing the 60i in post to slow it down? That would make sense, and if so then pure 60P should look great in comparison. Same with resolution, if you're de-interlacing 60i it'll probably give same res more or less as 720/60P. There do seem to be some concerns with the JVC codec struggling to cope at 60P though.
On the lens front, you can get adapters to put Nikon stills lenses on the JVC (and Canon for that matter) so can put telephotos on it.
Steve

The canon camera is NOT a progressive shooting camera, its a 24 "F" setting which is a 23.98 over a 60i image. This is why the canon will seem like it has motion blur, because the interlaced frames are having to deal with creating a progressive image over it. The sharper image will only be on a true progressive CCD like JVC's.

Yes Giuseppe, that's what I was saying, I was assuming he was shooting interlaced and therefore should get less motion blur than progressive. If shooting in the F mode then yes you'll get progressive-like blur but can only go upto 30fps and you lose your slomo possibility by de-interlacing.
Steve

Ah I see I see, I for some reason thought you were suggesting something else... but yes that is true. Forgive me, lack of sleep kills my reading skills haha.

As for a JVC owner, I can say that yes, its a great decision to buy this camera, to reply to the original post.