The FS argument is up to you of course. You could always rent a few different bikes, HT and FS of varying designs (single pivot, 4-bar, rocker etc) and see how you like them.
As for the riser, I like risers. However, if you find they aren't to your liking, I can't imagine a bike shop being unwilling to swap it out for a flat for little to no charge. On both the Nunu and the Caldera the hydro discs are pulling the rest of the components down. The Marz EXR is as low as you can go on the Marzocchi food chain (you won't find it on their webpage without doing some digging). And the wheelsets leave a lot to be desired. Konas in general have started to look a little overpriced to me, which is unfortunate as I've always liked them a lot.
On the Giant side you've got the Rainier, which has a wheelset I'm not familiar with, a fork no one seems to like, and avid mechanical disks which everyone seems to like. All this for a little less than the Caldera.
If you're a lightweight you might not mind the fork on the Giant, otherwise you might consider trying to get a different fork on it, or looking elsewhere.
edit: rocker, not rocket
Last edited by DiL; 06-04-03 at 11:56 PM.