I really do like what the authors were going for with this one, and even though my final verdict is conflicted at best, I still think Cell 6 is a fascinating effort.
• The voice acting is not the best I've ever heard, but still, the performances are great and the sound quality is also fine.
• The map is thankfully small, I like how the authors decided to not overcomplicate the level geometry (but what they've built is nicely detailed). The layout leans into the unreasonably mazelike territory a few times, but thanks to the size of the map, it's not really a problem.
• It's both an undercover mission and a detective mission, so it's safe to say Cell 6 does a couple of things in a different way compared to the vast majority of Thief missions... The problem is it's actually a keyhunt mission - and considering the small scale/amount of keys, it's often a quite ridiculous one. There are a couple of situations in which even pixelhunt is mandatory.
• While the undercover nature of the mission can sometimes break your progress, in my playthrough, ironically this caused the least amount of problems. Bugs (the elevator leading to an office) and a strange insta death were my main enemies.

I think my main problem with this mission is the first time playing it can be frustrating, but sadly I don't really see any replay value in it. As an attempt at creating an undercover/detective mission with great voice acting, I respect it a lot though.