Much better than I expected.
Due to the casting choice, I was expecting another Morbius - and while Mr. Leto can't play a superhero very well, he is excellent at looking like a "program".
The premise is a well done twist on the classic Tron. People getting sucked into a computer is now programs being spit out in the real world.
This wouldn't have worked, if it weren't for these 2 key points:
1) the programs are now Neural Networks, as demonstrated very well in the first scene. This gives them an agency missing from the previous Tron movies (besides the ISOs of course) that, once turned physical, makes them "fully alive"
2) They can only survive physically for half an hour, since they lack basis in reality.
The plot for this movie is the search for that basis, both as a McGuffin called "permanence" and as a philosophy.
Of course the music was awesome too, a worthy successessor to the Legacy soundtrack.
Overall I recommend it, it was made by Tron fans for Tron fans.