I like the hydraulic clutch.
Combined with a VPC it's just what I needed for the arthritic thumb in my left hand. I find that the friction zone is in the same place, even after substantial use, like a slow race, maze work, or a rodeo competition. I like that bar position makes no change or difference in the friction zone. By that I mean that with a cable, you experience flexing and bending when the bars are turned back and forth, lock to lock in one motion. This has a slight change on the friction zone as the cable movement often translates into small amounts of stretching or shortening, thus changing the friction zone. Most riders won't notice it, and experienced riders know how to adjust for it.
The downside to having the friction zone in the same place is that it is not adjustable. Some riders like the cable adjusted so the friction zone engages when the clutch lever comes right off the grip. Others like to adjust the cable so the friction zone is when the clutch lever is almost fully extended. You can't adjust any of that with the hydraulic clutch. That may be an issue to some riders, others can easily adapt to it.
I'm sure others will chime in with their experiences with the hydro clutch.
Mark
One other thing I'd like to add. The lever pull is very linear, or even and smooth all the way back. That may be the effect of the VPC too.