I bought some Heidenau K60s finally. Here's the rear comparison to My old Perelli MT90 Scorpions

And here's a comparison to the fronts

I enjoyed the MT 90s for what they were: 70/30 tires. They did GREAT on road

... Not so much offroad
I've only been on asphalt so far with the Heidenaus, but they are even BETTER than the MT 90s on asphalt!

We'll see what they offer offroad, but they gotta be better than the old Perellis. Way bigger knobs and grooves.
But be forewarned, they are extremely tough tires to put on. I originally bought a 150 rear and actually broke the band while installing it. Bummer

So I ended up buying a 140 rear off of Rockymountain. I bought the original pair off eBay for $275. Expensive tires, but they seem to be worth the $$$