I have had nothing but positive experiences with Hirsch.
My first experience was getting my 1999 9-3 a ECU upgrade. When I called Hirsch to ask about the upgrade, I mentioned I had a US spec car and they said no problem. So the big day came around and I made the 4 hour road trip to their shop in St. Gallen. This is when I gat a small scare. They had forgot that I mentioned that my car was US spec and weren't prepared for me. But then they comforted me right away by mentioning that they would custom program my car for the normal price of one of their upgrades. The reason they did this is that they had not yet made any ECU upgrades for any US spec cars, hence they are not OBDII compliant. They could have given me one of the Euro market upgrades but I would have gotten a permanent check engine light. So anyways, they proceeded to to write my program right before my very eyes. By the end of the workday they had improved my car from 192 hp to 227 hp. An improvement consistenet with their normal upgrades on the Euro spec cars. Also, torque was a quite good 328 Nm from just 0.9 bar or 13 psi boost pressure.
So for my second Hirsch experience, I decided to have them install a Viggen intercooler for me so that I could get a new dyno output on the same dyno. The price was surprisingly reasonable for the area, just $350 with including installation and dyno run. Power increased to 238 hp and 338 nm.
My third and ongoing experience is with my ECU rewrite. I had since improved the breathing of my 9-3 with a BSR Optiflow intake, 3" downpipe and racecat and the whole gamut of suspension and brake improvements. Anyways, on the power side, they agreed that I would benefit from a new ECU program to take advantage of the better engine breathing. Hirsch proceeded to rewrite my program and the power results were outstanding. 260 hp and 348 nm from 1.15 max boost pressure with 0.95 bar at higher rpms. Pretty good for a 2.0 liter with a T25 turbo.
The car did have a problem though. At reves below 3500 rpm, boost pumps up and down. They tried to find the probelm in the software, but no luck. They told me not to worry as they will work to find the problem and send me a new ECU with the fix for me to try out.
Also, they had changed the throttle response in the program so that I only got full boost at WOT. Otherwise, at 9/10ths pedal travel and less, boost came up a bit softer and with presumably more control. I did not like the idea of this, however, they thought I would like it. They asked me to give it a try and let them know how I liked it. After about a month with it , I concluded that I just can't get used to this throttle response so I gave them a call. They gladly agreed to return the throttle response to that of my old program when they work on the forementioned boost pumping problem.
So now this is where I am at. Hirsch is going to work on my boost pumping problem and throttle response early this coming week. They expect to have a reprogrammed ECU in the mail by mid-week. Hopefully it will have my problems solved and I can have all the power with the quality of their first upgrade to my car.
And, as far as I know, I remain as the only person with a Hirsch ECU'd US spec 9-3. And I am a very happy Hirsch customer at that. I'll keep you posted on the fix later.