Not sure if this hurts or helps.
I bought Fez day 1 when it dropped, but didn't get around to playing it due to a backlog. When the talk of a patch came up, being necessary to fixing game performance issues, I decided to just wait it out until the patch dropped. When the patch finally dropped, I read that it caused other issues and could not confirm whom it was affecting with 100% certainty.
So I let the unpatched game sit on my hard drive until it all got sorted out, and I learned some interesting things about patching on the Xbox Live service up until this past Saturday where I decided to take the plunge and play the patched game as a brand new player. This because it was said to only affect 1% of those with game saves in progress.
Well, I played the game to completion in one day. I did not get all of the anti-cubes, nor did I get all of the artifacts or maps. However, I did notice that in the last two hours of playing the game levels would load slowly, where the background would render in after the character appeared on screen, music would be choppy initially and a few times the game would play in a sluggish manner until the level loaded to whatever constraints it required for the visible area (if not in totality).
I am a veteran of 8 bit slow down and mused at the nostalgia Phil Fish achieved by creating an environment in which not only the music and graphics evoked an earlier time, but also re-created the memory issues of the carts of the past. While the above did not hinder my enjoyment of the game, I have to wonder what did the patch exactly fix, if the attempt was to resolve performance issues?
Maybe it has to be related to playing this game in an entire 8 hour day without exiting out and rebooting the game during breaks. I did pause a few times for refreshments, minor chores and exercise. So there may be something of value for Phil Fish, if he is reading this thread, to determine that there are some continuing issues post-patch. Be it the hardware, the compiled code or caching issues, I do hope he can take the game to a different platform and patch in an iterative manner that both satisfies what would constitute as a "bug-free" piece of software and his customers.
I enjoyed the game, overall, I do hope he learned something from this venture and in the process, maybe he has matured a bit so the next project he works on can be realized with less drama and come to market in the best possible state it can be with such a limited team.