it's very true the the stock airbox on the Z is good, most people change it for that extra sucking noise really
heatsoak: would CF be better than the rubber tube we already have?
I have a K&N Typhoon, which IMO has the best design for the Z if you want to replace the stock airbox, but yeah the filter needs celaning every 10k miles or so, I did it recently and it was really really filthy
Looks good though