Yes, I too have read Cooper's book. It's ok, but no more. Harry Yeide's book Steel Victory is a bit better if you are choosing a new read though.
As far as it goes, the Sherman wasn't that bad. Yes, the early versions did have a tendency to burn easily, but so did most WW II armored vehicles with gasoline engines and ammunition stowed above the lower hull. The US quickly moved to fix this problem by providing wet (water jacketed) ammo boxes and applique armor (those little plates on the side of the hull and turret) to minimize this problem. These proved very successful, particularly the wet stowage models that were substancially less likely to burn when penetrated than virtually any German tank.
As for armor, the US provided about 300 M4A3E2 Jumbo Shermans in the ETO. These received mixed reviews from the troops. Some liked the extra armor (they were virtually impervious to 75L48 fire and could take both the 75L70 and 88L56 at about 800+ yards) others derided their reduced mobility.
Then there were the in theater developed applique armor kits to upgrade the glacis on the M4A1 and 3 using additional 2" plate. This gives a Sherman hull armor equal to a Panther on the front. Most 3rd Army tanks received such a fix by late 1944 for example.
As for engines, the US only used 2 varieties in their Shermans: The Wright radial in the M4A1 and the Ford GAA V8 (half a Merlin...what a versitile engine that was) in the M4A3. The diesel models went to the Marines and Russians for the most part while the Chrysler multibanks went to the British.
Only the Wright on the M4A1 has the plug fouling problems. Any German tank crew would have gladly given a protion of their privates to get the reliability of that Ford GAA engine.....Turn the magnetios on, push the starter and, Boom! the engine is running...cold weather, hot weather, wet weather...after being thrashed for weeks...it still ran.
Just one more observation: The Soviet T34/76 really isn't any better than the Sherman except in cross country mobility (do note that there are well documented cases of US crews "hot rodding" their tanks by removing the governor and tuning them up to get 35+mph out of a Sherman). The armor and gun have little to choose between them. The Sherman has the edge in crew efficency.
So, on the whole, the Sherman isn't all that bad comparatively. And, it is sour grapes that generally on the rare occasion that the Germans did have Tigers present they had but a handful available. Quantity has a quality all its own....