Without starting a battle I would like to throw my "2 cents" into this discussion.
While researching my M1A1HA build I have acquired a dozen or so publications mostly geared to providing modelers with data and photos. So between them and a hundred or so photos from online sources mainly Prime Portal I have looked at nearly 400 photos. These include all versions on the A1 and A2 as well as all SEP versions. I have spent close to a hundred or more hours studying and think I can say conclusively that making hard statements about a specific version is like saying all leopards have the same spot pattern! I have been modeling one of two specific M1A1 HA with TUSK 1 protection package and I had to chose one or the other due to variations between the two. Both served together but have slightly different configurations.
I also have in my possession three different 1/35 kits of what is billed the same versions, but yet they are different. I have three different 1/16 kits, Heng Long M1A2, Tamiya M1A2 "static kit" and the Trumpeter M1A1. The level of detail and molding of the upper hull and turret are a lot a like. There are some odd differences in what is and is not included. IMO the level of detail for 1/16 scale is underwhelming on all.
The three are very different basically in how they are engineered because they are directed at a specific market.
Heng Long is targeted at the RTR market while the Tamiya is targeted at those wanting top shelf engineering and willing to build and the Trumpeter kit is a Static model pure and simple.
I can say that had the Tamiya kit been available when I started I would have chosen it for the engineering and the molding in styrene plastic.

I have learned to HATE the HL plastic, it is crap to work with but for its' targeted market it is solid. I have spent close to 100 hours bringing the HL chassis and drive train up to acceptable quality. The Tamiya starts out that way and I have considered using the Tamiya chassis under my HL hull and may do so at some point.
Just My Two Cents Worth,
Barry