Shooters: What have you learned?

[Grim Tuesday]

I doubt that next year will be a shooter game, but I can guarantee that some years down the road, there will be another year where a shooter is the de facto method of scoring. I hope this thread will be useful to teams when that year does roll around!

So what less than (or more than) obvious facts have you learned about shooter design this year? What problems did you run into that you weren't expecting, and how did you fix them?

I'll start off: Make a single axle shooter if you want backspin. And if you make one with two axles, make an easy way to adjust the squish and make it easy to take apart. Because you'll be doing a lot of that.