I have a few Sugino cranks and a forged ones are very nice. That said at least for the ones I have used the Shimano's with their ramps and pins shift better.
Kona used to claim sugino cranksets being lighter than shimano as their reason for fitting them. Now I have one of each to compare I now get it. There's a noticable difference!
As above though, the rings do seem to be made of cottage cheese or suchlike. I've fitted middleburns.