I also have a rigid ss and a fs Santa Cruz SL. Rigid SS's are awesome... as long as the decents aren't too rocky or have really big roots... or really big drops... ok it's somewhat limited, but if you know that going in, then what the hell... you have a built in excuse for going slow... Riding them does make you a more aware (better?) rider... you're forced to look farther down trail and plan your line rather than just ride over whatever is in front of you.
The only thing I've really done different to my bike from front susp/gears to rigid ss was wider bars. 660mm I believe. better leverage for those monster climbs, who says your arms don't do anything when you're riding a bike....