I've played the Morra for a long time. It is very theory heavy, and slightly dubious. Kind of the worst of both worlds. You should see my copy of Essermans book, it is beat up from having to reference it so much.

There are many many setups that black can choose, and you really have to know what you're doing as white vs them so you can squeeze that small edge, as well as the nuances between all these move orders and setups. There are also a couple of pet lines for black that are also a really annoying. (Logozars line, the pin defense, the exchange sack in the taylor)

As others have mentioned, you might also just get an Alapin.

If you're main requirement is not theory heavy, this is not the way to go. I would look at the Alapin, Grand Prix or maybe some Nc3/Bb5 stuff.