Well, it was a very pleasant experience - I booted the Fedora KDE LiveCD, and ran the Fedora installer from the desktop which took about 20 minutes. Once I had rebooted, I used the package manager to the /Java Development/ set of packages (which gave me Iced Tea and ant). I then downloaded and unzipped JBoss AS 4.2.2.GA and Seam 2.0.0.GA, deployed the booking example, started JBoss AS, and booked myself a suite!
I did notice that the application seemed more faster than normal, so I took a look at my favourite completely subjective performance measure -- how long it takes JBoss AS to start with just the booking example deployed -- and it seemed good at around 20s.
This piqued my interest, so I did a highly unscientific test and installed the Sun JDK 1.5.0_14 and the Sun JDK 1.6.0_03, and (using Seam and the example compiled by JDK 1.5) took a look at how long the server takes to start.
I found that using JDK 5 to boot the server it took 32s, using JDK 6 it took 25s and using Iced Tea (JDK 7) 21s -- definitely going in the right directions! I then compiled Seam and the example using Iced Tea, and (running JBoss AS using Iced Tea) got a startup time around 19-20s.
Of course, this no match for a real performance test, but I found it interesting.