I have a 1 piece Mustang on my 07 Ultra -
It DID move me back a noticeable amount, but it did add the comfort of being able to stretch my legs into a much more comfortable touring position. I like to rest my heels on the floorboards and my toes against my hi-way pegs, and this seat allows that easily and comfortably.
You definitely will want a backrest. I have an HD Screaming Eagle adjustable backrest on mine and like it a lot (no, you don't necessarily need a Mustang backrest)
It also lowered me just a bit, which is ok, cuz I'm vertically challenged anyway - 5" 8" w/ 30" inseam.
For nimble riding, cone dodging, or other parking lot stunts, one would definitely want a seat that put you up on top of the bike like a solo cop seat or such.
As for comfort, I did 14 days from Atl to SoCal last year without problem, and many, many more miles around the southeast as well. I might get it re-stuffed this year as this seat now has about 30k on it, and I hear Mean City is doing Mustangs now--but, maybe not...

NOTE- if your seat is new, it does take some time to break in to your butt...but once it does, it's pretty comfy and instead of being ready for a hospital bed after 60 miles with a stock seat, 600 miles days are pretty easy.
NOTE 2 -- The wife likes this seat too....

Hope this helps

 

I know this isn't an answer but on my last bike I had a Mustang W/backrest and loved it.

 

Like another poster I had one on my previous bike. Made a ton of difference in comfort for both me and the old lady. Waiting till I can ride the new girl and see how I like the stock FLHTC seat but I'm guessing the next thing will be a Mustang.

 

I had the Regal Touring Seat on my '08 Road Glide for a while and really liked it's quality and appearance. But it was a bit firm for me and didn't seem as roomy as the HD Ultra Classic stock seat. I didn't think that it moved me down and back, but rather about the same as the stock Road Glide seat and stock Ultra Classic seat. I have since sold it and am now using a HD Sundowner, which I really like.

 

I have the Mustang on my 07 U.C. and like it (about 2 years now). However, other than the stock seat I have not tried others. I did not notice any difference in riding position, height or back/forward, but it did seem a little wider and when stopped with feet/foot down make it seem a little taller. From all the responses, looks like everyone has a different feel and comfort setting.

For me, I really like the seat over stock and have no plans to change at this point.

 

I have a regal touring on my bike , good seat. Sent it to MCC & had it lowered 1 in, moved fwd 1/2 in and narrowed at the front, put in 2 layer memorey foam, now it's outstanding!

 

If your not sure which way to go on a new seat. I strongly suggest calling www.meancitycycles.com Allen can help you out rebuilding your old seat at a much lower price. At least call and talk to him and go from there. He rebuilt mine on a new bike at the time. I am very happy with the results. Mustang may be a great seat but rebuilding was a good option for me.

 

I always heard good things about the mustangs so I tried a two up touring ..The wife loved it, I didn't.. As far as positioning I didn't notice much difference but the deeper saddle cut me high across the hip and put my leg to sleep after about 50mi ..I tried to break it in for about 3000mi couldn't take it anymore and put my sundowner back on, some love it but it didn't fit me ...If you are still interested PM me I have an almost new one on my shelf ...

 

07 FLHTC ...I have the Wide touring seat and it sits me very slightly lower and rearward but the comfort compared to the stock seat...especially the lower back support and added to that the backrest (HD brand) has made 50000 miles of riding over 3 years a lot more comfy...Hey there might be a better seat out there like Corbin or the HD Sundowner but i haven't tried it yet.

 

I had a Mustang seat on a metric and it was awsum. I put one on my glide and it was not the same. The bride, after about 10 miles wanted the Harley seat back so I returned it. For me I could not get comfortable and I stuck like glue to the surface. I like to slide around. The nice thing about Mustang is that they give you time to try it and if you don't like it they will take it back. I wish harley would do that with thier hammock seat.