> Con: Since it's Linux-based I think online games with anti-cheat won't work, which seems like a significant downside in terms of utility.

Correction: it's some online games, not all. According to areweanticheatyet.com, ~500 games with anticheat work. And if you ask me, the ones that don't work are ones not worth playing in the first place - these companies (on Windows) employ malware-like anticheat systems that spies on you, causes BSODs and upgrade failures, slows down your PC etc. It's clear that these companies don't respect your PC, so why should they deserve your money?

As for whether the Steam Machine is worth it or not, if you don't really care about Linux, then it's not worth it, because you can build your one rig for way cheaper. The Steam Machine, especially in this market, is for people who really want to support Valve and the work that they're doing towards improving Linux gaming, it's to show the industry that there is indeed a growing market for Linux gaming. People who're buying the Steam Machine right now are mainly these kind of folks, people fed up with Windows and Microsoft's monopoly.

If you don't care about all that, then don't get the Steam Machine.