This time my experience is fresh and horrible. We went after work for some beers to restaurace Antal. Service was really slow and we waited long time till we could order our five beers. When they arrived, there were quite empty to call them half liter of beer.
No matter what we drunk them and ordered another one, this time asking for full beer. Well it didn't arrive and our complain followed. Waiter seemed to be surprised that guest dares to complain and looked very angry. However after some minutes we got full beer. All of us agreed that it was filled with water. This time we found phone number to owner and called there. Owner was at the bar and ensured us, that there was no water in our beers.
We still resisted as we had ordered food. For most of us it arrived, only my colleague didn't get his one. But after several urgencies, it arrived and by accident he had some paper in it.
However we were still strong and resisted and ordered another beer. This time it seemed to be okay. Last surprise came when we payed as waiter calculated somehow two more beers than we have.
Simply avoid this place if you can. Looking at other experiences (in Czech only), we're not alone who has such feeling about this pub.