I've played and enjoyed both. I'll say I liked Turing Complete a lot more but it depends on what you're looking for.

Shenzhen I/O is more a puzzle game where you get thrown a bunch of miniature puzzles you solve via programming cleverness to advance some overall story theme while enjoying general puzzle solving.

Turing Complete is more a digital circuit sandbox which starts you off in a direction of building up more and more complicated components and abstractions and you get more and more freedom as you go until you've unlocked everything and it becomes a big sandbox for you. There is technically a loose "story" but it's more or less just something to give context around what you're currently trying to build in the level not an actual plot. I.e. you could read every line of "story" ahead of time and it would not detract from your first playthrough as it's not really a narrative.

I will say Turing Complete starts off with a very limited feel though. The farther you make it into the game the less and less you see guardrails.

They're both worth getting. I haven't finished either game, so I can't talk about end-game value for either, but it certainly feels to me like Turing Complete is an educational game with puzzle components, while Shenzhen I/O is a straight puzzle game.

Both are a lot of fun, and very well-made.

Shenzhen I/O (like most Zachtronics games) has some nice worldbuilding touches like the printable datasheets for the made-up electrical components, and a barely-there programming language manual.