[Kevin Leonard]

Competitive success and learning about engineering do not have to be separate ideas.

There's a student on our team right now who is disgruntled. He thinks we focus too much on competitive success, and he believes that building the same traction drivetrain each year doesn't help students as much as building something crazy, like a kiwi drive, that may not contribute as much to competitive success.

I'm going to try to address both your situation and my teammate's situation simultaneously, so bear with me.

In my humble opinion, students working with a kit-bot chassis can learn just as much, if not more as students working on a kiwi drive- however these might be different things.
There is so much to learn about a six-wheel drivebase that you can't learn from a kiwi drive. Factors involved in pushing matches, like current draw and breaking traction, as well as the advantages and disadvantages of different gearing ratios. I've learned near everything I know about these topics from my involvement in FRC on a team that uses nothing but traction drivebases.

And as you said, your shooter didn't always work when you wanted it to. By investing time into your kiwi drivebase, you lost time to work on your scoring mechanisms, which ended up unreliable. Tons of engineering hours can be put into making these other systems great. Reliability is much more difficult to engineer into a system than teams like 1114 and 254 make it seem, and having some time to work out the kinks in your subsystems- whether through prototyping or through practice time- is what makes these teams great.

And despite what some people might say- it is possible to be competitive with a non-traction drivebase in the right game if you so choose. The two teams that come to mind are Team 2052, KnightKrawler from Minnesota and Team 1425, Error Code Xero from the Pacific Northwest.
2052 uses a mecanum drive most years, and 1425 uses some sort of kiwi drive (correct me if I'm wrong). These teams are successful not because of their drivebases, but because their scoring mechanisms are so well-tuned and their drivers so practiced. 2052's drivers in 2013 were among some of the best in FRC.

What would I suggest for next year? There is no situation that has yet occurred in FRC where a 6-wheel traction drive is a bad idea, and the kitbot is a good and affordable drivetrain that can provide many lessons in engineering.

However, if you intend to stick with a Kiwi drive, figure that out Week 1 and have it built by the end of week 1. Then work on your scoring mechanisms and have your drivers start practicing with driving Week 1.

And good luck.