Cork inserts:
MSR
CA Plus 5000
And rubber inserts:
Broken Fusion bat (Unsure if UK or Asian made...)
Red Ink LE
Hunts County Triumph Cyclone
Helios Atlas
Hybrid Handles:
Laver and Wood PB with C-ten handle (Has cork inserts)
Pakistani made Plain bat - cork-rubber-cork handle (An absolute gun according to friend I bought it for)
I didn't actually realise that rubber inserts came in different colours until I looked at my Helios' handle a little while back! Generally speaking, if you dig your nail slightly into the insert, you will find that rubber ones are slightly 'bouncy' while cork tend to be harder.
The fact that the C-ten handle has cork inserts suggests to me that cork inserts may perhaps give a slightly stiffer handle than rubber inserts, but I could be very wrong. They may be used instead of rubber as cork is lighter, or maybe even because the handle just constructs better with cork! A question for JL himself I reckon!
One thing I don't know how people figure out is the 'piece' number, like a 12 piece cane handle, how do you tell? From a glance, I can't really tell at all, I would call all of the handles I have popped up 4 piece cane handles, but I am not sure. What does the number of pieces do to a handle anyways?