John, you know Clark made your Brute right????
They are both good machines. I purchased the Brute. A very good friend of mine had a lot to do with the development of the Defender. The defender was the the original design and Clark developed the Brute in a attempt to improve on it.
I have a lot of time on the Brute and a good amount of time on the Defender. I prefer the Brute, but it is strictly do to what I am used to.
If you want one with a spray system and tank pick the Brute, IF that is not important to you pick the Defender.
More important then which machine you pick is the pad driver you choose. There are 3 types of pad drivers
1) The combo Bush and Velcro driver, this is the one John orders for his machines. It is the one I prefer. You can run cotton, synthetics,and VCT style pads with this driver
2) the all brush driver, this is the one Clark will normally give you if you dont ask for a different one. It is very similar to the pad driver for the
RX20. It works well with Synthetic pads and VCT pads but is very hard on Cotton style pads.
3) is the all velcro driver, these run very smooth. The are excellent on cotton but dont work as well for VCT pad and are just ok for synthetics.
There are multiple suppliers of the Brute and Defender, John G is one but there are others and they can be ordered straight from Clark at Orbitech (the Manufacturer) Shop around for the best price. Clark offers good service and will take care of you on that end regardless of who you buy from.
What ever you decide to buy, verify it comes set up the way you want it and not the way your particular supplier normally orders them.