I just installed new CFR Slip-ons on my 2011 Ultra Classic. These are the new models with the fluting going thorugh the entire internal end cap. I'll give you the pros and cons and other observations of mine.

First, a brief note about my bike setup. I basically only have a stage 1 setup with Kromewerks 2-1-2 pipes (no cat) and a SE air cleaner. The slip ons I had installed previous were SE Fatshots.

Installation of the CFR's themselves were no big deal, as the Fatshots came off with little trouble.
The time consuming part was dealing with the Kromewerks heat shields. There were a PITA to take off and put back on. I'm thinking I could have avoided removal of the sheilds by just loosening the clamps and working the torca clamp around it. One more note on the sheilds, I had to spread open the short left side shield a bit to get to fit because the CFR's are fatter than the fatshots at the point where the shield covers and I could not get it to fit right without the mod.

After install, I flashed a Fuel moto map with my powervision and I have ran them for a few days.
Here are my pros and cons:

Pros:
They look great. The chrome is excellent and once I modded the one heat shield, it fits better, IMHO, than the fatshots.
The sound is unique, as others have said, it sounds like a cross between a harley and a big block chevy.
Your bike will sound like it's modified even if it isn't
My bike runs cooler with the CFR's... it probably has more to do with the richer FI map, but conditions that would have put the bike into parade mode before, are not now.
I feel no noticeable loss in low end.. On a dyno you may see it, but I don't feel it.

Cons:
These slips ons are LOUD, there is no doubt about it...significantly louder than my Fatshots. My Fatshots got loud when you hit the throttle hard, but even then the CFR's are still louder.
At idle and low speed they have a percussive component to the sound that may bother some riders and probably more bystanders.
The biggest con for me is the low resonance "booming" effect I get from these when rolling away from a stop. It may just be because it's a new sound, but time will tell if I will get used to it.
Because of the cons above, I have this constant fear of getting pulled over when passing a cop and receiving a ticket for loud exhaust. On my first ride I went by three seperate squad cars and feathered the throttle (which didn't make too much difference) hoping I wouldn't get their attention.

Summary:
I'm on the fence about whether to keep the CFR's on the bike or not. I do like the tone, although it is LOUDER than I am used to, and they look great. As far as the volume, I had the same feeling when I put SE slip ons on my 1995 1200 Sportster, but I did get used to it in time and kept the mufflers on until I sold the bike.
It may just come to down to what the wife thinks...she rides with me quite a bit, but hasn't since the CFR's were installed. I've pulled into the driveway with them on several occasions and she hasn't made a comment on them being louder, but we'll see what she thinks on her first ride.

If I do pull them and sell them, I just chalk it up to a few hundred dollar mistake. It isn't the first time and won't be the last. I'll put the fatshots back on and be happy. I wasn't UNHAPPY with the fatshots, I was just looking for a different (better) sound.

Here are few pics of the bike with the CFR's

 

As any change give it time ,,,, my problem it im always changing things ... good luck,,,

 

I've had my CFR's for several months now. Bike came with Cobra Billet Tips and they were way to subtle for my taste. After installing my CFR's, I can honestly say that I really like them. Nice aggressive sound. My wife doesn't mind the sound just as long as she can hear the music from my saddlebag speaker lids. Take your wife on a nice ride and see what she thinks about it...if she don't like em, sell to me. Thanks.

 

If you decide to sell, pm me. I have the Jackpot Pro-Touring 4.5" mufflers and love the sound. I am confident that the sound is very similar to the CFRs as they have the same body shape and likely similar baffling. Anyway, do pm me if you end-up not liking them. I like the looks of the fluting.

 

I had them for less than 30 miles. Too freaking loud. I couldn't deal with it.

 

And I thank you every time I fire my bike up. I love the sound.
My neighbor told me the other day that when I fire the bike up, his dog goes nuts. I try to idle out of my house and road as quiet as I can until I get a ways away to respect my neighbors. I replaced Rineharts with these and prefer the CFR

 

Don't get me wrong the sound was badass but it was too much for me. I know,I know I'm a puss. Hahahahahahaha

 

Good luck in your decision and your quest. I am finding myself kinda in the same boat these days.
I went with some CFR Knock Offs awhile back. Loved the sound they put out and everything was just about right.
I decided to ditch my stock headpipe & put some V&H Dresser Duals on-mostly to get rid of the heat and also as part towards running a Stage 1 upgrade. This did the trick in getting rid of the heat, but now these slip-ons are border line too loud for me. For the most part, they're fine when cruising. But for those long rides where you're in the saddle all day long- the drone & volume is starting to wear on me.
The biggest change is when you crack it open now- it is hellacious.
Initially, there was a certain entertainment value in seeing the dead rise from the grave, small children running in fear and the occasional glares from the cagers here & there.
But that entertainment has now grown a bit tiresome and I am looking to tame it back down.
I want to avoid beginning a never-ending quest going through various combo's of slip-ons- searching for that ever elusive sound that is "just right".
As of now, I have decided to go with some American Customs & give them a shot, mostly due to feedback I have heard here & the cost factor.

It's too bad you can't "rent" slip-ons while trying to sort out what it is you are looking for. Kind of like trying out different windshields or seats at your local HD before buying.
Now there's a hell of an idea for some entrepreneur!
Whoever jumps on that one- just send me the royalty checks and all is good!

 

Honestly, if it wasn't for the that low resonance "booming" sound just as you get rolling, I probably wouldn't be debating on whether to keep the CFR's..
Once rolling, these pipes sound every bit as good as I thought they would.
I knew they would be louder than my fatshots, so I really can't complain about that.

As the previous poster said, I am afraid the CFR's might get monotonous on all day or multi day rides.. regardless if I keep them or not, I am keeping my fatshots and would seriously consider switching them out for a multi day ride..

 

I was thanking you becasue I am the one who bought yours