Tough but fair
On a 30 to 40 peoples group, around 5 succeed. Sometimes more, sometimes less. That makes an average of +/-10% succeeding.
I do not think it is more or less in comparison with other Airlines. At least, they give nearly everybody the chance to get to the interview, wich is really not the case with other companies.
So, it is a fair assesment. The psychometric is tough. Small Apple laptop. Be prepare to manipulate your mouse for 3 hours and do not take a break. Being fast with the computer mouse is really here the key.
The theoritical test is not difficult if you review your ATPL: Meteo, RNav, Pan Ops, Nav, Principle of flights.
For the rest, sim is strange but it's a sim. It do not flight straight, but once you understand it, it's OK. One ILS with G/A and then one non-precision approach.
If you reach the interview, be yourself. Safety is the key.
And yes, Innsbruck is really a nice place, so enjoy it!!!
Good luck