I am not sure if the reviewers are talking about the same restaurant. The one I know is beside Roosto. I always go to Abou Aly to get roasted chicken because the lines at Roosto are SOOO long. Abou Aly's roasted chicken tastes the same or better and there is no long wait. I usually go there instead.
On the other hand, there is a restaurant named Abou Aly El Shamy in Ali El deen plaza. I ordered chicken from them thinking that it was the same Abou Aly as in Hosary and it was not very good, and sort of expensive.
So maybe people are confusing the two? All of my experiences with the Abou Aly in Hosary have been good.