As an ex-student of Aviation Career Center (ACC) - Maribor, I can just give the advice, to stay away from this ATO in Slovenia and to talk to the previous students.
I can confirm everything what Deckbacon has said, the lectures were very poor, as 10% of the ATPL theory phase was spent in the classroom with the same two instructors, who have very little or no experience at all, just reading out aloud the content of the Oxford ATPL books - wasting time.
The aircraft that were used for the flight training, were in a bad shape, and nothing was done about it, even if it was reported. I have experienced all the issues myself, i.e. flaps (that would jump to the up position during approach), stab trim (that was running away during departure), engine (cylinder, and lead on the spark plugs), one student has experienced an electrical fire and a another one an engine failure.
The Chief Pilot has some anger problems which everybody knows of (including the management). On one of my first training flights, he made me fly with no airspeed & altitude indications (blocked pitot tube), after telling him that I felt uncomfortable to continue flying like this, he exploded on me, asking me how I would dare to question his decisions, since he has more than 8.000 hours of flight experience, including hours on - Cessna Citation Jet -, compared to a stupid student pilot like me (I also had to pay for the Chief Pilot's ferry flight to the maintenance due to this problem), but that is just the cherry on the cake...
He has many unwritten rules, and if he doesn't like you, then you are in trouble, as he also enjoys threatening students for no reason.
Money has a high priority, therefore students are paying their 'training fees' in advance, even if no training is taking place.
You are not being treated as a student or customer, but as a cash cow, that is being milked till the end of the 'training'.