I went ahead and got the SS. It wasn't much more $$.

 

I have the "18 and I love the sound, but it is a little to loud for me personally. $140 installed with stainless 2&1/8" pipe. Put it on before I got my Thorly Tri-y and did not notice a great performance increase. the header set it off though!!

 

I didn't bother. If it rusts through they will replace it. If I lived somewhare whare they salt the roads I would go with stainless.

 

It sounds a little too loud than I've expected at the 1800~2800 RPM (way too loud for my wife, she didn't want to ride in it at all). and it seems like I lost some low-end torque. I had it on for only 1 (ONE) week and had to take it out and put the OEM back on, I did keep the tip though. I've wasted $100 bucks in a week.

May be the 24" is not that loud.

 

I've noticed that after breaking mine in I seem to experience a low level drone at freeway speeds but only noticeable when the radio is off.

As far as loss of low-end torque, can't say that I experienced that. If anything I gained back some loss of power through the larger tires and the 3" lift.
Maybe the Amsoil and Deckplate mod have something to do with that?

 

I also wasted about $100 when I originally put on that 14" magnaflow. The 24" is borderline for me as far as sound level. I would not want it any louder.

 

I hope my 24" isn't too loud, I have a 14" turbo muffler now that the wife complains about. The 24" is huge, 31 inches overall, but I'm adding a highflow cat and headers too so maybe overall it will be louder.

What are you going to do with your 18"? Maybe you could sell it to someone wanting a louder exhaust.