How sound is the Morra?

Over this weekend I have been sitting in on a FIDE Trainers Course being organised by the FIDE Trainers Commission for players in Asia and Oceania. There have been a number of excellent presentations (from some of the world's leading trainers) and I have picked up a number of new ideas for coaching and training.
One of the more surprising ideas is that while most opening gambits have been refuted (or defanged) by  chess engines, there are a couple that are still playable (for White). These are the Scotch Gambit (4.c3), the Evans Gambit, and the Morra Gambit. The last was a bit of a surprise as it never seem to catch on at the top level. But as suggested by the lecturer (GM Oleksiyenko), I looked to see which top GM's play it regularly. GM Emanuel Berg looks to be the highest rated exponent of this gambit, playing it for much of his career. While he hasn't won every game, he has won enough to show it is playable, including the following win.


Berg,Emanuel (2579) - Luch,Michal (2448) [B21]
POR-chT Porto (9.5), 20.08.2016