I've had two Hirsched 9-5 Aeros and one Hirsched 9-3 1.8t Vector. Both a significant improvement. I chose that course because both cars were still under warranty at the time. I've had no problem any of the cars due to the tune.
I believe that Hirsch worked along with Fredrik form Maptun on some special tunes.
Hirsch are only available via a Saab Approved Service Agent. Some are better than others. Maptun do the basic tunes via their DIY box. If you don't want to do it that way, you would probably have to deal with Neo Brothers, who have a fairly mixed reputation with customer relations.