I have Stillen Gen 2 exhaust. I find it loud. I believe Gen 1 is even louder. The other mods are relatively quite in comparison to your Gen 1 exhaust. However, the exhaust does make good power across the the rev range and even better acceration on the top end. Enjoy...

 

I have a Gen2 as well. It was very loud. I had to tone it down a bit with some bottle mufflers. Now it sounds amazing! Just loud enough when you are cruising to let you know something is different and at WOT there is no mistake. It probably cost me a couple of HP to make it quieter, but my wife wouldn't drive with me when it was louder .

 

I just installed the Gen 2 about a month ago (05 5AT Sedan). Was a little loud at first but seems to be getting quieter (maybe I'm just getting used to it). The Gen 1 is louder (way louder) had a buddy who ended up taking it off because it was too loud. I hear that the Gen 1 does give a little better performance though. IMO they both sound good

 

The Stillen CAI makes the car sound good. Big growl with throttle, but no drone otherwise. The exhaust, on the other hand, has been too much for more than just a few here. But as stated above, have a muffler shop weld in a good straight-thru design resonator instead of ditching the system if it's too much. A simple 18" resonator can make a huge difference.

 

When I helped a member here install his suspension (D-specs & oem coupe springs), he was kind enough to let me drive his car the 20 miles from the install site back to his house. He had the Stillen Gen1. I totally and compleatly understand why Gen1 owner's complain about drone under load between 2k and 3.5K. I got to experience it first hand, it's their and it's is not mild. Outside of that, sounds great at idle, makes power and offer's a terrific wail on the run up to redline (listened to another Stillen Gen1 sedan do a run, I wouldn't drive a friend's car that way). But it does tend to get loud on the inside when it's in drone mode.

 

I used to own the Stillen Gen 1 exhaust, IMO, it is not so loud to a point that it is not bearable (i indeed like how loud it is and it sounds sweet). Yet, many of us found the droning a bit unberable at highway speed.

On the other hand, if you do want to keep the Gen 1 and want to tone the droning and noise level done, you can look at tweaking the rear muffler as well as the X-pipe (by adding another straight through resonator)

I believe the "real" difference between the Gen 1 and the Gen 2 is the design of the X-pipe and the rear muffler

Good luck with the Stillen (I still miss the nice exhaust sound that it makes, especially at the track...i got my cousin to drive my car, and i was so amazed how nice the stillen sounded in the perspective of a pedestrian)

 

My wife thinks the Gen1 is loud. I think it's awesome. I think it's even more awesome every time I'm pushing it past 3500 rpm on the way to 5,000. The sound, the power...delicious. It probably is loud but I like it. Pretty much a personal preference. People have different tolerances for the sound it produces. The occasional drone is far outweighed by the upside IMO.

 

The Stillen Gen 1 Exhaust is fun around town, makes a killer sound IMO, the problem is on the highway where you will get some serious droning, it was so irritating I ended up replacing it with a Nismo Exhaust.

 

I have gen1 with Stillen CAI and Ztube - those combined with MDE 1/2" spacer give the cart a nice throaty tone... admittedly it is a little loud at WOT, but you will completely get use to it (at least I did). As others have mentioned in older threads it either mellows out after a few hundred miles or you just get use to it because it seems less loud than when it was brand new.

As for as drone - I guess it can be annoying (again, you get use to it after a while) but you can add dynamat or B-Quiet in your trunk and under rear seats and it will cut the sound in the cabin. DaveO has done the B-Quiet; there is a write in Sport Z Mag... I’ve gone to B-Quiet's website, and it is definitely a mod I will be doing in the future.

Hope all (or any) of this helps your decision.