^^ Thanks woo. I got the same measurements (within .1 mm) when I did some measuring and fitting. Had to go through quite the pile of reducers...
Anyway, onward. So. I've got an RP23 on the bike now! I went to a local shop and they couldn't believe what they were hearing and then seeing with me trying to get the Fox shock to the same width as the AFR from Specialized. Apparently, I'm nuts to try to replace the AFR with the Fox. Hmm....
Anyway. It is better. A lot better. Still not 100% perfect, but much much better. This shock behaves a lot more predictably when descending and even while climbing. It feels more plush, like it gives some better feedback from the trail so you can actually feel things. As far as I'm concerned, it is a drastic improvement over the AFR.
Climbing is interesting. With this shock (and yes, you can have them revalved to completely change characteristics - in fact, maybe the AFR shock could have been revalved to play a little nicer...) you have to pick between an active rear suspension and one with very little movement and activity while climbing. Flipping the switch to the firm side of the ride really reduces pedal bob/feedback greatly. Which is great unless you want some plushness while climbing and want the rear to conform to the trail better through and over roots/rocks/kittens... I spent a great deal of time yesterday on a long climb (road, smooth trail, very rough trail, very technical trail - in that order) playing with the firmness. I found that on rough trail sections and (where I spent most of my time) if I could sit and spin reasonably smoothly, I'd prefer to leave it wide-open, letting the system do its thing and to actually smooth out the trail. Any extended standing efforts required throwing the switch into the firm setting. It just moved too damn much. Which is a compromise I can deal with. Obviously on the road, and on smooth trails where I wanted to stand, I'd leave it firm and hammer away. Very technical riding (Waldrop trail, anyone?) was interesting - I never felt like I had it where I wanted it.... but in the end, I left it open and used the kush to plow through the techy climbing/rolling terrain...
Descending was far better than with the AFR shock. It handled high speed stuff well and never seemed to dive too much when I'd pump/throw it into corners. It also was nice on slower speed descents through trails with more rock than dirt, a steep grade, water bars with 2' roller step-downs into rocky boulders... Just very predictable and easy to descend with. The "dead" or "hollow" feeling I experienced before is gone. Awesome.
After all this, I'm left with a question. This shock was valved (supposedly, right?) for use with a 6.6. Is there a difference in valving for shocks mounted horizontally vs vertically? I ask because I think this shock should feel a bit better. I'm being picky again, and maybe it is because of my limited experience with 4-Bar/Faux-Bar/Whatever suspensions... but it doesn't feel quite as plush as it should. But, I've only got two rides on it and it is a vast improvement over the stock setup. Anyway, sorta curious about valving for that stuff.
Bottom line: IMHO, this shock is much better for riders really wanting to feel the trail. It fits a more aggressive riding style and is a great compliment to the rest of the bike. So, now I'm left with time to get a lot more miles on the bike, really evaluate how I feel on it, and make some more changes to it... I'm also still really happy with the weight. Even with a Speedball seatpost, the bike climbs easily for a 6" travel trail bike. Okay, that's enough for now.