Hit the woods with the new tire.
First up, I kept the road air pressure of 25 psi and gave her a go. It behaved as I expected . . . kinda like a knobby that you could spin up and roost at will. The inline block pattern offered less grip than say a 606, but still did better than I thought it would. For non-technical terrain there is no real need to air down, if you don't feel like it. Just have to deal with the limitations of a harsher ride and less traction.
Next, I sat in the driveway and, progressively dropped the pressure with me sitting on the bike. For my weight (200 pounds nekid) the sweet spot (tread flattening out to the point that all the tread blocks were in contact with the ground) was 8 psi (If you are lighter you will reach a flat footprint at a higher pressure). The footprint was H-U-M-O-N-G-U-S.
So, aired back up with my little compressor that runs off my bike's battery and headed one of my favorite play grounds.
On the trail, I aired back down to 8 psi and went right to "Heartbreak Hill" . . . a climb where many an ego was crushed and tractored right up that sucker. It was like cheating! Had to be a fluke; had to be. Two more attempts; two more times I made it. Hmmm. NEVER made it that easy with a MT-43 aired down, never.
Rocks were engulfed by the tire, held in place and just rolled over.
Wet roots, logs and steep hillside traverses all went insanely well.
Mud was next: Much better than the MT-43, but not quite on par with a fresh 606.
Only real downside to 8 psi was on fast corners the tire felt "squirmy" like the sidewall was rolling over a bit. Maybe 9 psi?
Pros: Unreal grip/traction
Smooth riding (felt like a suspension upgrade, lol)
Best tire to date for me
Cons: Big, heavy tire
Not quite up to a 606 in the mud
Personally, I have found my new favorite, do it all, rear tire.