Sorry for the delay : )
I'm hoping to get some video of the exhaust this weekend. Overall, I love it, but I keep throwing codes due to the fabspeed. I'm working with WheelSTO (reseller) to see what my options are now.
The Akra slip-on is definitely louder than the stock axle back, but the sound is more uniform. It is bassy and aggressive, but there is some resonance at startup. This resonance goes away once the car is heated up - about 2 mins. If you live in an apartment or condo, this might be dramatic in the early AM. I might have some small leaks down there, or this may simply be how this will sound. My guess is that it is very close to the "normal" sound of this combo.
With the windows up, you can still hear the exhaust, but it is not overwhelming at all. If you drive the car awkwardly, in bizarre RPM/load combos, you can get some hum and additional volume. I really wouldn't call it a resonance because it doesn't really shake the car or bother your ears. With the windows down, the car is fairly loud, but still sounds great. One is still able to control the volume if you are driving in a nice area, parking garage, whatever. It is not crazy loud all the time like some race exhausts.
The sound of revving the car is simply amazing. It sounds similar to the full Akra setup, but there is definitely additional volume and a touch more raciness - I like it better than the vids I've heard. You can hear how unique this engine is; the exhaust enhances it IMHO. If I could just get this CEL issue sorted, it would be the perfect exhaust for me. Something tells me I'm not going to find a solution to the fabspeed problem though and I will have to chose to live with the CEL, or put the primary cats back in.
One issue my installer did run into is that the slip fitting for the fabspeed kept leaking. This is the joint where their HFCs meet their xpipe. After struggling with it for a couple of hours, they decided to tig weld it. I also have to get under the car to check for a potential leak - I saw some exhaust accumulation on the xpipe. I'm not sure if the X is leaking, or if it is something upstream. I was hoping to get to this on the weekend, but getting the winter setup on was more important.
There is my mini-review for you : ) Please ask whatever is on your mind!