My rebound dampening setting was about 2-4 clicks in from center. I'm not 100% sure if that is contributing to my problem or not, but the rebound characteristics of the bike do not seem to be a concern for me. Really, my only concern is that it would appear that my ride height is a tad lower than before, and in the twisties where there are bumps near and around the apex of the curves, I get more "pogo stick effect" than I used to. In my mind, both of these might be attributed to a spring that is getting fatigued, and/or worn oil in the shock. It is not leaking.
I've emailed RockyMountain ATV to see if they can tell me technically what the superseded part number means. Will share with the group anything I find.
Also, I sent an email to this guy, on recommendation from someone in the other sandbox:
http://www.smsuspensionsystems.com/#/contact/4569827795
He called me yesterday (Saturday) and spent 15 minutes on the phone with me, answering questions and making recommendations. I thought that was real nice of him, considering the weekend. Of course, he recommends altering both the front and rear suspension. He indicates that for my weight (210 pounds), and including 100 pounds for a full top box and camping bag on the pillion seat, I need a spring that is in the neighborhood of 1000 pounds. He quoted me "about $1,500.00) to re-do the stock shock, including a new spring, new seals, new oil, and reworked dampening internals, as well as new Race tech fork springs and valving, along with new oil and fork seals and bushings. Of course, I can change the fork springs myself, which could save me a couple hundred bucks. Regardless, I'm just not too crazy about spending $1,500.00 on my bike with 50K on it.