It's very popular with German admins and some of those in the EU.
It was a solid platform when I used it, but the biggest issue I had with it was with support on their support forum. If you did not speak/write German then you were usually waiting for bit for a response until one of the developers happened to stroll by. And they did provide very good support, better than even what used to be done by the developers of Xenforo on their support site before radio silence became the watchword of the day at XF.
They had some very decent add-ons and offered more core products than Xenforo did.
I used it back in the 4.x days (I think it was) for a period of time on a Linux site I was running. I never renewed that license and after a certain point you are basically buying it new again and I decided on my "play" sites I would use open source offerings instead of a paid script.
In fact, if I was going back to a new paid script for a site they would be high in the running, even above Xenforo as they are still actively getting updated products out and do converse with their users.
