It does reduce drag and it does give you a tiny HP gain but it ruins your clutch in minutes. Always use the bike manufacturers oil and fill to the right level, another not so clever trick used to gain a tiny power increase is to reduce the oil level in the drive-case, Oils must cool the clutch as well as lubricate it, never cut corners here and never put additives of any sort in drive-case oil which cause plates to stick and glaze, invalidating your warranty and ruining your clutch.
This was a basic clutch kit for a Kawasaki ZG 1000. The steel plates and springs were in good shape so they went back in. Have put on 300 miles or so and the new clutch feels great
EBC, name brand for motorcycle repair and restoration.
So far, so good on this application/installation. However, I am not on the road yet, working on other restoration and repair functions. But seems to have solved the 30 year-old clutch dragging issue due to the OE plates packed with who-knows-what junk and disintegrating slowly, due to age.