With the factory installed Firestone tires I would get stuck in wet grass! It was so bad that I thought the 4x4 system was defective. The treads, on the Firestones, started separating from the belts at around 40K miles. It sounds like there are a bunch of good aftermarket tires out there.

 

I had the same problem on an F350 I had. It was the Firestone Steeltex or something like that. I hated those tires. There was a recall on some of them for the issues you described. I hated it when you had to get a running start to go up a 10 degree incline when the grass was wet.

 

Shocker.... a Ford with Firestone issues!!!

 

I just bought a set of these Dunlop Rover MT Maxx Traction tires and I love them so far. Haven't had them in mud yet, just snow and they will pull me through 18"-24" of snow up hills fairly well. They also have the mountain snowflake symbol on the side meaning they are snow rated.