Clutch...Synthetic and Blends

How does the KZ clutch react to synthetic and blends? Has anyone experienced slippage?

Here's what I've been using with no problems at all:

Mobil 1 Racing 4T 10W-40 is recommended for four-cycle motorcycles which specify the use of a 10W-40 engine oil. It provides excellent performance in motorcycle engines that are designed with a common engine/transmission lubrication system or where the engine lubrication system is separate from the transmission system. In the case of the latter, follow the manufacturer's recommendation for the type of fluid to be used in the transmission. Mobil 1 Racing 4T 10W-40 engine oil is also designed to provide the proper frictional characteristics necessary for wet-clutch engine/transmission systems. Mobil 1 Racing 4T 10W-40 exceeds the requirements of API Service Categories SH, SG/CF, CD, JASO MA and has been fully tested, both on laboratory dynamometers and in the field, to provide optimum horsepower and acceleration.

Synthetic oil won't make your clutch slip. What MAY cause slippage is the friction reducing additives in some oils (both syn and regular) that are used in "energy conserving" oils. If it says that on the label, it MIGHT cause slipping. It never has in my KZ 750, but some claim it does.

I use Kawasaki S4 10W40 synthetic oil and have had no problems.
The engine revs smoother than what it did before when I used conventional oil.

I use the Valvoline 4 stroke motorcycle synth. Doesn't cause me any issues and it is easier to find than some of the others. (any murrays or autozone around here has it)