i shot the photos of this '91 F40 for RM, you can see the thread i posted with them here: http://www.ferrarichat.com/forum/showthread.php?t=376579
The euro seat design looks more like a nice racing seat, really great in every aspect (design, feeling, weight, safty). The US seat may be easier to get in and out, also this seat looks not that narrow like the euro seats.
Its awesome how much one can learn from post like these. Thanks for that! I doubt i'll ever own one, but it's cool to know that kind of stuff!