I got my Borla CatBack installed a couple days ago, and I am EXTREMELY happy with it! It's a very nice deep tone, and there is no in cab drone whatsoever.
It's actually very quiet in the cab, and doesn't interfere with conversation.
At the higher RPM's it definitely starts to growl, and I would confidently say there is a power improvement. I've also noticed the truck idles at 600 rpm, doesn't fluctuate and is very quiet, the truck loves the Borla!
I haven't had it long enough to say if mpg has increased, but I'm betting it does.
I put a video on youtube of my comparison to stock.
I ordered part #140140 which is for the double cab long bed Tacoma, you can buy the system for other cab configurations as well.
Install was a breeze, after getting the stock exhaust removed, I had this one bolted up within 45 minutes, all I needed was a 15mm socket and driver, and a pry bar to removed the rubber bushings holding the stock exhaust up.
If you are looking for a good exhaust system, I would put this at the top of your list.
Here's the Video, I'll be making another video with more clips.