Congrats on the Multi SL. We were both looking for Futuras and ended up with something else. Lol
Yeah, while state farm was dragging it's feet I watched 3 of them sell on this side of the country and in my budget/fly and ride range. Then once I got the insurance check not a single one popped up for 2 weeks. Two minutes after I got home with the Multi an 04 with 40k on it got posted for sale in Long Beach. I'm starting to like the Multi more but I think that's because I've ridden her more and she's mine so I'm not stressing over dropping someone else's bike.

Yeah, trying to find some cheaper ones that fit the MTS.
I can't speak to the replacement mirrors aside from "yes I want them, too".
I like the Sargent. It is better than the early model wooden plank seat I had on my old bike. I would guess for real distance you'd still want a seat pad, and if I really wanted distance comfort I'd buy the Airhawk and Alaska Leather sheepskin pad. The Sargent is perfect for short rides especially if you'r moving around a lot - the padding gets thin sitting still. The seat came with my bike as did nearly everything else on it. Some guy dropped loads of money into it, found he was too short, and sold it to another short guy who added to it and also found himself too short. I bought it with barely 4k on the odometer and (proudly) several thousand dollars of farkles on it all for less than most were selling for.
That said, I've had the Acerbis hand guards on my last bike (non S). I liked them, but they interfered with the Throttlemeisters; I preferred heated gloves and Throttlemeisters as the TMs not only worked great but functioned as vibration dampers on the bar ends. I still have them, I think with all the small parts. One side is scratched pretty bad from a parking lot drop.
I have the GIVI topcase with Admorelighting brake lights. I like this setup very much for the rear brakelight brightness when night riding/ commuting. I don't have side cases but really want them. I am not sure if I'll do OEM (they DO look nice) or Pelican cases with the Strada Avventurosa (sp?) mounts. Side cases will make her wide for lane splitting (not something I do at all often, but it's a consideration for you).
Ahh, so how slick is the Sargent seat. Aside from the board like qualities the other thing that bugs me is that with textile pants on I'm sliding all over the place on it. Especially when it's raining which is a little unnerving. I may just slap some tech grip on the tank and see if that helps me stay planted.
Strada Avventurosa brackets look pretty slick, I totally want their slider bars and to mount some lights in a similar fashion to what they have. One of the bikes I looked at the owner was using some much smaller, leather skinned ridged bags because he found the OEM side cases to wide too. I think the best solution in the long run is both and slap them on as necessary.
forgot:
The 03-(?)05 bikes had too short mirrors and side stands. Both were cheaply upgradable. I heard Duc NA was even covering one or both for free for a while. The side stand was hazardously short. Ther was a guy on MTS.net making longer mirror stems for cheap.
Yeah, this bike has the longer kickstand replacement already. Didn't know about the longer mirror stems, I'll look into it though.