Hi Matt, welcome back to the sport and a hello from another LGBT roboteer!

You builds look good though there is a better option than the Sabretooth for your AW in the form of a NanoTwo LT from NutsandBots.co.uk, might save you a few grams with the smaller circuit board. How much does it weigh a the moment?

I love the look of your BW. For the rear wheels, perhaps the same diameter but a harder rubber to permit better turning perhaps?