Fair enough that you're still within warranty, but practically speaking, that rig is 5yrs old now. I certainly understand your frustration - I replaced mine out of pocket - but ride is subjective afterall and technically speaking, there's nothing wrong with the Bilsteins (though I personally hate them) - they're just too harsh for my taste. Some have had success getting Koni's put on as a good-will gesture. I feel I probably could have too if I were willing to make the trip to Michigan (I wasn't.)
I ordered through Precision Frame - $400 and did the replacement myself. It does make a tremendous difference! I think if you order the parts, you'll soon forget about the cost.
I've found Spartan to be tremendously helpful via e-mail and phone. Most recently, my rig was out of alignment. The shop indicated it couldn't be adjusted any further as the camber was maxed out. I contacted Spartan by e-mail, they took it upon themselves to look up the shop, contact them and give them instructions for making further adjustments.
Personally, I couldn't ask for better service. My previous rig was a Monaco; suffice to say, I couldn't be happier than with Newmar and Spartan.