I'm used to the 90X and I find it a marvelous camera. With the F90x you can't use the "G" lenses, so for example a 70-300 lens will be more expensive because yoiu need to buy the "D"-lens.
Otherwise I think the F90X is more solid than the F80. However... A friend of mine has an F5 and F80 and he likes very much the F80...
In Belgium you still can buy the "secretary"-software that enables you to have a connection to your PC, cables are also available but be aware... the foftware isn't very cheap, neather is the connection cable.