I've used them for years now - since they came out. Not for the auto clutch feature initially, but to have a LHRB, as injuries prevent me from using a foot brake.
They take a bit to get used to, as does any change.
I've used a few different Rekluses, BUT, if they are reliable and as good as they appear / I think them to be, I would recommend the Revloc Dyna Ring over a Rekluse. They are cheaper, and retain the ability to still bump start your bike, by just adjusting the clutch cable. With a bit of set up, I'm sure you could rig up an 'on the fly' clutch cable adjuster (the lever type) to give you an 'on the fly' bump start feature - a real plus on a nasty down hill. Not having bump start has been one of my concerns over all these years - to regain it would be of great use.
Revloc essentially started the auto clutch thing, so I have no doubts about them producing an effective, reliable unit in the Dyna ring - as I said, this is coming from a long time Rekluse user.