Is Allbau reliable?

Hello folks of Essen! It's me again.

I’m currently looking for a long term stay. I found a super nice one on ImmoScout24 managed by a rental company Allbau. (Funny thing is, their office is literally right across the street from the building I visited yesterday to check out another flat.

When I went in their office today in the last 30 min to ask for information, the receptionist didn’t seem to speak much English, and my German is lame, so she just gave me a QR code card and told me to fill out a enquiry form online. I’m about to go back to the company tomorrow after class or maybe give them a call.

But before that, I’d like to ask everyone: how are Allbau’s apartments? Is this company reliable? Is their reputation and service any good? Any insights would be super appreciated <3