Procfs, most definitely.  Saved my ass with `ps' twice now.

the problem is that we've had several security issues with this
file system and while we believe we have them all, i'm certainly
not going to rule that out!  the same goes with other weird
filesystems.
   
   Yes; however, the QUOTA code is likely used by far more people than the

yes, many people rely on the QUOTA code.  it should be enabled 
in default kernels, IMO.