+1 Uncle Paul. Agree with everything and recommend one for long hauls or bad backs. I had the HD non-adjustable on my '08 FLHT and HD Adjustable backrests on my '13 and '14 FLHTKs. While I'm healing up from a multi-level lumbar fusion, the backrest gives me enough support to keep my saddle time up.
If you put some long days in I recommend trying the adjustable model. Being able to adjust the position on the move is nice and being able to make small adjustments to your position can make a big difference over time.
I got mine from either Surdyke or New Castle HD; can't remember but I'm pretty sure it was the standard 20% discount.
Installation was easy but the instructions did make it look like the switch goes on top of the mid frame head deflectors instead of under it.
Just like Uncle Paul said, I pop the backrest off but if I'm parked somewhere sketchy.

 

Forgot- I'm 5'8" and the backrest does help me backing the bike up too, especially when there's a slight incline.

And bigdumbnoitall00 is right too, the stock passenger position and non-adjustable backrest did bother my wife. I moved the tourpak back with the DK custom products kit. Very easy and very quick.

 

I have a 2012 Limited and the first mod I did before delivery was a HD Adjustable back rest. I have have them before on my metric and without. Long rides they really help me from too much slouching, and help with riding longer. Expensive but very adjustable. The other thing I like is you can adjust them on the fly to change pressure points on your legs and butt to relief some soreness before it becomes too annoying.

I can't speak for any other back rest, only used the Harley brand on the Harley.

 

Thank You for all the feedback..I will be getting the adj. HD backrest. Wife should have enough room she is fairly petite, maybe big hips I mean butt...All crap forget about it...Not a 300 pound gorilla or such....

 

Utopia backrests. Great product and super nice people.

 

Thank You RaceRadio this is on my "Toy" List