BTM is an "open diff" technique. It causes the spiders gears to alternate from right-to-left dominance, and it works on any open-diffed rig, (done it many times with open-diffed Jeeps). It honestly doesn't do much by itself. But on the H3...the puter will step-in and work with BTM to take full advantage of moving around the power to the wheel that needs it. The puter needs to sense wheels spinning at different speeds to do anything. BTM simply uses the brakes to fake the puter into searching for traction at one of the corners. Without using the brakes...the system still works in the same way. The only difference is that you have to apply more throttle and induce wheelspin for the puter to sense it. And as we all know...that's not healthy for your H3. So BTM is a way to induce traction control at a relatively low speed, without mashing the throttle and spinning the hell out of the wheels. Simply put...it allows you to crawl slowly and still use the TCS, something that is unique and special about late model TC-equipped rigs.
Last week I wheeled with several groups, and I saw completely different techniques between old school "gun & go" rigs....and late model IFS/TCS rigs. FJ-cruisers, Xterras, and Hummers make very difficult obstacles look easy (and downright boring to the spectator), and its all due to the electronic systems and proper BTM technique. There will always be a place in my heart for a 6000 rpm assault up a rutted-out ravine but, seeing bone stock IFS rigs tackle the same terrain at 3 mph is equally amazing...just in a different way.