Just a beautiful new series that has the drive system upgrades that they have been working on for the last few years. These are such an upgrade from the EXP series just a few years ago that it literally takes your breath away.
I would still spend the extra $100 and get the C 900 personally. The larger motor is well worth the extra even though both have a lifetime motor warranty. Look at the rest of the warranty because it is only 1 year.