i like Academy kits.

Having drunk from the Asuka/Tasca well many times, any other would taste very bitter

Like anything else I guess IMO no Sherman kit is without its faults. Asuka/Tasca don't seem to gave the rough texture of a Sherman casting, lack casting numbers and don't have rotatable periscopes (and at least some don't come with photo etch things like periscope guards). Dragon kits, well they have that old Italeri style suspension, many of the transmission covers are a bear to get to fit right and I hate their drive sprockets. Academy as has been pointed out have their faults, especially their track. I haven't done the more recent Tamiya M4A3E8 but their earlier Shermans had their problems as well. So it's really up to what you want to pay, what you can get (the Dragons and Asukas seem to go in and out of production, the Dragons really quickly. Sometime in 2017 they're supposed to re-release their M4A3 (75) and when they do I think I'll buy around 5 [I always wanted to have a platoon of them in the same scale]) and what you're willing to correct. Fortunately there are work-arounds for all the various faults with the various kits.