Had that exact setup on my '07 RK and loved it - mama did too. Then traded RK in on '10 RG. Couldn't x-fer seat to new frame so I got dealer to toss in a new style HD Sundowner.
The Sundowner was crap all-around and total crap for her. The pillion pan area was bent up so far that there was only room left for about 1" of padding. Therefore, spent the $ on the 2-piece Mustang again, a set that fits the new frame. OUTSTANDING results. Just a good as my old set-up.
BTW - The new solo isn't exactly the same. There's a bit less wrap-around height in back but that actually suits me a little better. Of course, might not mean anything at all for someone else - I "carry" a personal belt accessory and less seat back there is a little better for me.