JxL,
I've been riding mainly SS bikes since 2001 and have to agree with Countzero for people who like to just ride bikes, SS's rock (less faffing time) My main bike at the Mo' is a Dialled Love/Hate (new frames coming soon for £265) but after 69ing the love/hate I'm building a Surly Karate Monkey as the advantages of 29er wheels work for me.
Pro's : bigger wheels roll over things without falling into holes quite as much, so a less "choppy" ride
The contact patch is longer giving more grip for a given width of tyre, also you could argue higher air volume, but it probably doesn't make a massive difference. I found there was lots of cornering grip
Con's : Bigger tyres/wheels/tubes weigh a little bit more and that weight is at the furthest point from the axle, so it might feel a bit slow to accelerate compared to a 26er.
It's getting better but, you won't get as big a choice of tyres/tubes and rims in 29er sizes as you will in 26in
People point and laugh at the freak (that might just be me though
)
It's probably best to try both before you splash the cash, maybe go to your nearest Gary Fisher dealer. But On-one are doing some great deals on frames at the moment, and the slotted Inbred seems a nice simple solution. Maybe even use this forum to "test ride" someone elses bikes. If you are in Northants I'll have a 26 and 29er (to suit a 6 footerish) SS you can ride.
Rust, Yes they are steel, but there is a fair amount of Chromium and Molybdeum (sp?) in the mix. I have an old Steel frame that hasn't had a scrap of paint on it since 2000 (hence Trustyrusty) and apart from some serious surface rust, it seems pretty sound. I had a S/H On-one a while ago that stained the paint from chips in the paint, but then like most proper SS's it had a tough life and was used a lot in winter and thrown in the shed dirty, they love it when you treat them rough