Yes, he stuff can be quite varied in quality. The Cornelius books were written in a time when Psychadelia was at its height and this probably accounts for much of its oddness. There is also a Cornelius movie
The Final Program which is extremely odd but with its tongue firmly in its cheek. a bit hard to come by but interesting nonetheless.
Amongst my favourite Moorcock is
The Dancers At The End Of Time trilogy (available as part of the SF Masterworks series). you might want to check it out.