Just had the "One Ball Mod" done... removed the resonator box.
Not only has it shed some weight (As I myself need to do!) but it's definately mad a difference in the 65 - 90 miles an hour area.
Pick up has more pull too.

The local exhaust shop did a great job... they cut off the pipe from about the middle of the car (It was rather rusty!) and then welded it to the exhaust pipe after cutting off the resonator box.
A nice, clean install.

The sound isn't as loud as I was expecting, in fact it sounds about the same to me... other than a few more rumbles and pops at deceleration, but again, it's not obnoxious.
No drone on highway speeds either.

Great, cheap mod and gained some torque from it too.
(Shop charged $60 and it took about an hour).

 

I did my one ball mod last august and loved it. I never noticed a power increase but I definitely noticed it to be louder. Its pops and burbles alot more now and is actually noticeable at throttle now. I love it.

Try driving in a gear lower than you normally would and you'll see its quite a bit louder. just going 20-30 mph in 2nd makes my car backfire like crazy when I let off.

 

Wonder if it's because they cut more of the pipe away than just cutting it at the first bend? - They cut from about under the tans.

Not loud at all, even at higher revs / lower gear... but I love it all the same!!

 

I've been considering doing this myself, hmmm...

 

It's a no brainer... Just don't get hosed and spend more than $100... And find a reputable custom exhaust shop.