This kit is one of the poorest Abrams kits produced. While the basic kit was fairly accurate (but crude) as an M1, Esci/AMT/Ertl skimped when they produced the "M1A1". They basically switched a few parts between the M1 and M1A1.
This leads to several problems:
1. The turret is too small (frontal armor was increased)
2. The turret bustle rack was incorrectly made. The actual bustle rack goes straight back and does not cant inwards.
3. They made no adjustments to the lower hull. They failed to add the NBC over pressurization system in place of the left sponson box.
4. The rear engine grill was crudely molded.
5. The center guides are molded in the wrong spot. They should be between two adjacent track blocks and not centered on a single block.
This is all I can think about off of the top of my head. When they were released in the late 1980s, the only other Abrams kit in 1/35 scale was the original Tamiya M1. This kit was the first one to offer the new style turret blast panels, 120mm gun, and man hole cover.
As a model, it is not too bad. It builds OK and looks like an Abrams when completed. If you want to build even a semi-accurate USMC Abrams serving in Iraq, I'd suggest finding another kit such as the new (expensive) Tamiya M1A2/A1 and the DML USMC OIF M1A1.