Go with the 3DBotMaker, much better product and more return on your investment.
The Max Traxxx is a good backup if you need it. Also not bad if you're looking to mod something together and just need the electronic guts, but otherwise it's kind of flimsy.
I've taken one apart and it's very simple switches inside...I had plans to make the mechanic part more reliable by making alternate trigger flippers.
That's where I was headed most likely, seems to be a good product.
I agree, the 3dbotmaker is the way o go. It's no-contact so that's the main plus. And it's simple and accurate.