I haven't been posting much on this forum recently, but just came across this thread.
I had been having similar problems with my clutch.
Tried everything to fix it, but finally discovered that the slave cylinder bracket was simply deflecting as I depressed the clutch pedal.
Fitting the well known brace modification completely solved the problem.  In fact the new brace pulled the slave mounting bracket forwards by at least 10mm while in the released position.

Definitely a good modification as it made a big improvement to the way the car drives.
I have also fitted the brake servo reinforcement bracket.  Although it stopped that deflection problem, there was no noticeable change to the way the car drives.

Read More...