Hi Bad,
Personally, I use the Powertrax "
No-Slip " system that JR referred to earlier. It is a great improvement as it makes little to no noise/chattering when engaging/disengaging and it doesn't lock upm so tight that the tires chirp going around the corner unless you're near the steering lock.
What I really like about it is it lets the former "no-snow-go" become an artic cat, and yes it allows you to let down two strips of rubber. And to top it all off, all one has to do is remove the spider gears and follow the directions.
In other words, I highly recommend it, even at $400.