I read this play for school in the original (older) German language which made this a not so enjoyable experience. 
First of, I understand what Lessing was trying to do. The motives and themes are clear and everything revolves around it. Sometimes it feels inauthentic because of that. The charactes and situations felt forced just to get the wanted result. Besides that, most of the characters were stereotypical and one-dimensional. Except maybe Daja and the monk. I really gravitated towards them since there actions were surprising and left room for interpretation. They weren't perfect. I also liked Al-Hafi, he was the needed comedic relief even though I think Lessung didn't intend to. It cracked me up how he appeared two times and was missed the complete second half. *Random dialogue* oh, where is Al-Hafi? That's the randomness I like. The end was fine, everything felt wrapped up, no complaints. 
However: If you think that this play is still important (message wise or for basic reading) and you want people to read it, preferably GET it, you might need to give it a more modern translation. Please. I understand the importance of the original, that's why people study German literature. But for a student and normal reader it would be much more accessible if you give it a new edition. I'm talking accessibility here, reading this is not accessible at all. I had to look up words and read into some history afterwards. That's my take. I'm open for discussion and might change my view but after my first read that's all you get. 2.5 stars.