two NICs - channel bonding - tradeoff

[Christoph Wasshuber]

Assuming one has two 100MB NICs per node, is it
always the best to channel bond? Or are there
applications which run better with two separate
communication channels.
I could imagine an application where one has two
kinds of messages. One kind is a short message but
highly 'urgent'. Only after the message was delivered
can the calculation continue. For example a
synchronization message. And then another type of
message which is higher in volume but is not
time critical. So one channel would stay most of
the time empty to provide the lowest latency for
the urgent messages. Where the other channel is
stuffed to transmit non-urgent data.

Do I gain something with running two separate 
communication channels? Or do I fool myself?

Chris....