Could someone help me understand the pros and cons of L4 vs Minix 3?

L4 is supposed to have blazingly fast IPC, and that's very important
for microkernels. Is it possible for Minix to have a similar IPC
system? I have a moderate idea of how IPC works on Minix, but not in
L4. The Minix version looks efficient to me, but I would love to know
if it can be improved.

What else is special about L4 besides IPC? I've read that it is non-
portable in purpose in order to make it faster. This is interesting,
but it's hardly something that Minix could adopt. Minix wants to be