I have a 'Ferracci' slipper in my 749 R from ProTwins.

It is absolutely fantastic and transformed my 749R when it replaced the standard 'slipper' that Ducati fitted.

The original Ducati slipper clutch allowed the bike to 'freewheel' when coming into corners as though there was no engine braking which was a bit daunting the first few times it happened especially when coming into a corner at speed.
There was quite a few posts about this last year and most 749R owners had the same feeling.
I was told that Ducati were indeed replacing the clutches but my dealer made enquiries and said that this was not the case which resulted in me buying the 'Ferracci' one myself.