I always got the best improvement from finding specific problem bots (look at the KNNPBI) and trying to design a specific feature that would help against the kind of behaviour they showed. Usually it involves watching a lot of battles. Test beds are only to make sure that nothing is broken against other bots when this is happening.
It is really about the size of the testbed you want. Best would be the whole rumble. Minimum is probably something that shoots HOT, something linear, something simple VCS, something simple WS + VCS, some PM, and a tough top-bot or two.
And from what I've found, fixing bugs almost always gets better results than adding features. So make sure you don't have bugs, and don't have any bad assumptions.
- Thank you for your response about the test bed, I agree with the bugs part. I jumped from 28 to 26 with Bullet Shielding(2 days of coding) and 26 to 23 with a bug fix.(Stop position calculation)
- I just realized I had been calculating wave locations wrong since 10 months. I think I will add "First robot to enter the top 30 with wrong wave calculations" =)