Yes, there are a few resons:
1. Lack of resources
We didn't quite have the resources we needed to put it together in time this year
2. Strategy
Reviewing the game, we determined that the multi drive would not be a sufficent advantage and it would require a major design change.
3. Pre season design/strategy
It looks like my thread from last fall was removed, so I'm going to put a link to my paper here. I put up a paper last fall on strategy, both in the design and functionality. I've gotten quite a few good comments on it.
Basically, we're sticking with what we're good at, what we know works.
Trying new things is great and all, but when and why are two important reasons. Just check out the paper...
I have to say though, that I am very pleased with our standard drive this year. The design improvements have done us justice, and it operates much smoother than last year.
Here's a link to the paper:
http://raptar.net/stuff/RobDesNut.doc