I have (or maybe I should say - had) Bridgestone Trail Wings on my XT600.
They were worn to around 75% once I bought the bike, and now they are at around 60% thread left, and on my experience:
sh*t on gravel (packed - quite good, loose - sh*t)
sh*t on sand
sh*t on grass
and quite shi**y on asphalt (dry/wet) too: on various occasions I had felt the back wheel drifting in a junction when I was turning quite slowly.

Lithuanian riders say - there's no "all season" boots when your feet aren't cold in winter and not too hot in summer. The same goes to "all road" tires, which suck on all terrains.

Mitas, as far as I know, have different hardness rubber for different tires. Some are harder (let's say, for stony roads), and some are softer (sand, etc.).

Here's a couple of links to tables of "rubber hardness" and some pictures of the tires themselves. I know it's in Lithuanian, but tables are in English and pictures with model of tires sound the same in any language.
I bet you can find the same info if you Google a bit.

Tables:
Techninė informacija | mitas-moto.lt
Pictures:
Padangos enduro kelionėms | mitas-moto.lt
All other tires:
Motociklų padangos | mitas-moto.lt

My solution: SM wheels for road use (GOOD grippy SM tires), and MX wheels for off-road (front tire Mitas C-19, rear Pirelli Scorpion MX Extra). I had bought Mitas C-02 for rear tire, but changed my mind and got it studded for winter use: C-02 is quite soft, wears quick, but anyway awesome in the off-road. One disadvantage - those smaller side knobs, which bend in the corner and rear wheel can get unstable. That's why I went with Pirelli, as it has big knobs all round. And wears less on road.