Reiserfs was pretty good, at the time. At one point, it got nerfed by Linux maintainers introducing bad changes against Hans' advice, resulting in damage to the filesystem reputation.

But Reiser4, which never got merged, was insane levels of amazing in latency and ops/second, and yet excellent in throughput still.

Reiser4 was a team effort, and the other participants have been maintaining it irrespective of Reiser's imprisonment.

Today, there are some legitimately non-crap filesystem efforts, but they are either not mainlined and not very active (Tux3) or not Linux (Hammer2 from Dragonfly).

XFS could be made less crap; The main complaint I remember from Hans (dentries shouldn't be packed with inodes) does still stand. Metadata work such as a simple ls on a non-cached directory taking forever and a day.

I am most hopeful that when Matt Dillon declares Hammer2 done, porting efforts will make it widespread in open source operating systems.