I clean my '07 MCS intake valves every week with a little carb cleaner while idling. I have a plastic straw inserted into my intake after the I/C and it does a great job at keeping them clean.
I just bought a K04 hybrid, upgrade I/C and performance downpipe.
117k miles
2) catch cans
Alta intake w K&N
did new clutch 5k ago.
Replaced many engine components, doing water pump when i replace the turbo in a few weeks.
so far so good but i don't abuse.
I run 10/40 and change every 3-3500 miles.

Matt