Magnaflow #15986, 5" Exhaust system

[JGrosso]

I installed the Magnaflow #15986, 5" Stainless Exhaust system yesterday, and so far I really like it.

Some notes on the system.
#1 - The system does not look the same as Magnaflow shows on their web page. I think the picture on the web page is a 4" system. Here are some of the differences:
#1a - The down pipe from the turbo starts with 4" tube from the V-Band clamp on the cast elbow, then once the down pipe clears the transmission (about 1/2 way down) it goes into the 5" tube.
#1b - There are no exhaust hangers "on" the muffler. The hangers are on the tubes going into and out of the muffler. The muffler does have a nice polished look if it matters, and some of the tubes looked almost polished.
#1c - The tail pipe tube is two peices. The tube comming out of the muffler goes over the axle and about 1/2 way down the back side of the axle where the tail pipe with the tip attaches (The tip is welded on.)
#1d - The system came with the nice stainless band clamps, not the regular type exhaust clamps show in the photo on Magnaflows web page.

#2 - The muffler core is not 5", it looks like the inside core diameter is 4", so even though the majority of the tubing is 5", the muffler core and part of the down pipe are 4".

#3 - Installation was pretty easy. The whole job took about 3 hours in my driveway, and most of that time was getting the old exhaust system off the truck.

The new exhaust system sounds really nice, and is not too loud unless I really accelerate hard. I probbably only have driven about 70 miles with the new system, so I don't know about any mialage increase.
I think it may be worth some power, but I have no dyno comparisons.
I'm sure removing the stock muffler and cat should be worth some power gain.
Seat of the pants says maybe 15 HP?