I am totally hooked. For the past weeks, I have driven this
simulation excessively, something in it is totally addicitve. The attention to detail in driving behavior and system simulation is excellent, even the smallest technical nuances and differences in acceleration and breaking behaviour of the several bus types are modelled, from physics down to sound. For the time being this simulation has brought my interest for any other racing, driving of flying sim practically to a full halt.
Users at German and British Amazon give it just excellent marks. There as well as in German forums, several bus drivers described how incredibly close the physics and system simulation are to reality, under all driving conditions.
The sound is awesome - practially identical to reality in all details and nuances, really! And the bus models also vary in details. They all sound 100% identical to reality. Sound even changes when you open the windows.
Especially regarding sound, this simulation to me is now my official benchmark for reproducing reality. I cannot remember any other cockpit simulation doing such a perfect job in this regard.
I want to point out that there is also plenty of atmosphere if you combined heavy weather (rain and snow) with darker time of day, or even night, the graphics they have implemented are excellent, but do shine best when using them not in clear bright spring weather.
It's a bit surprising for myself that thgis fascinates me for so long time now.
By subject, this might not be the most complex of all simulations, but it is difficult nevertheless, and what it does it does unbelievably good. For that reason, I now see this as a truly hardcore simulation. I even learned to love the menu interface which at first is a bit rough around the egdes - but quite powerful.
Meanwhile, several additional tracks have been released by the community. But I have not checked them.
Meanwhile many videos have been released at youtube. Esoecially those focussing on bad weather and night rides should catch your attention.
For newcomers, I recommend to drive not in the rush hours, there is much more traffic, and many trucks, making your lanes at some parts stressfully narrow.

Traffic density and pedestrian density vary with time of day.
Currently no other cockpit-simulation of any kind in use over here. And this due to a bus driving sim!
If you have a general interest in vehicle simulation, consider this to be a must-buy. Prefer it to any train simulation, subway simulator and any other bus game there is. This is a true gem under an unconspicious surface.
If your rig allows, increase the default density for cars and passengers. When the traffic density mimics the real traffic you meet in Berlin - that is when the challenge starts!