eraser tool limitations

Hi

Are there any more features to the eraser tool than size or shape?.

I was hoping for the capability of softening the edge and a slider for quick reconfiguration of nib thickness.

I've rarely used the tool until recently; but now find it very useful in a particular process but very limited.

I know photopaint employs greater scope for this sort of thing ie. the object transparency brush - but I'd rather stay within Draw for this work.

Thanks Colin