I have the BT Thumb on my BH75. Happy for the most part, but it is limited because it is fixed, not hydraulic. (It is what it is) My first one wore out the main pivot point and started to get sloppy, so I contacted Bro-tech about it and he immediately sent me a replacement at no charge. Best customer service I've ever experienced!
I move a lot of rocks (boulders) which does create a lot of sideways torque on the thumb, so wish that pivot point could be a little more robust and have two prongs or be wider. I also move a lot of logs. A single spike at the bottom of the thumb would be good for that application, but hey! it is what it is and I couldn't live without it.
For occasional or medium duty use it's great. If you're using it every day, I would lay out the $$ and go for a hydraulic unit with two prongs if you can.
Again, could not live without it.
