I dont know... Kawasaki and yamaha have had me hook, line and sinker for the past few years.
This past year Suzuki's dediction on the R&D of their bikes have been bar-none. They were the first to put out a production 450 with fuel-injection for 08. Although they got most of this technology from the lt-r450. I know a lot of people say "stay away from fuel injection for the first coupe years". Well i say BS! They have had it going for awhile.
But back to the 250f catagory. I am now a die-hard zooker fan. IMHO the rm-z's have the best handling of the bunch, and I know that many will vouge for this. They might not have the absolutely strongest motor of the bunch, but its nothing a little jetting and tweaking cant fix, right? All the bikes have around the same horsepower and torque.
And I know someone later in this thread is gonna say well its not about power... its about the way the power is put to the ground... Well you can change the "Hit" with a different sprocket..Durr.
If i were you, i would see if i could try all the bikes at the track or wherever you would noramlly ride them.. then decide from there
But i would go with suzuki..