I just replaced my clutch plates to remedy a "funkiness" in the clutch feel. It felt as if it was slipping and occassionally changing the engagement/disengagement point in the lever within very, very short time periods that I thought shouldn't be a result of just heating up. The old friction plates didn't appear to be any more worn than the brand new ones, but they've been in there for a long time so I thought it'd be the best place to start.
The outter & inner baskets are grooved, but only slightly so. I can see the marks, but they only feel like very small indentions (nothing like pictures I've seen of badly notched fingers). I didn't bother to file it. I just figure a new basket will be necessary soon. Also, on the inner basket, where the first friction plate rests, the outter edge had some small damage around the outter edge, like it had chipped. There were two of these chips, no more than a half a millimeter in width and about an inch long at the most. What does this indicate, other than normal wear?
After the install, I took it for a brief spin around the barrio, and it felt fine. These are the stock baskets on my '98 250, btw.