I do believe there might be a thread or two already on the milforum about the best tanks in the world.
There are a handful no doubt of the world's most sophisticated fighting machines. The German Lepord the British Challenger the Israli Merkava and the South Korean and Brazilian MBT models just to name a few.
Try searching the milforum's for key phrases like best tank, or a specific tank designation.
The examples I listed above are all confirmed cases were the tanks have some sort of firing control computer or range finding component, which owes partially to the M1 A2s success. Also the crew training methods of that country also pay a huge amount towards how successful a MBT will be. As well as sustainabily.
Another reason the M1 A1/A2 is so good in the field is because the U.S. has the massive amounts of logistical resources and well trained man power to back it up.
Same with any modern battle tanks, diseal or turbine, computer or auto loaded, any tank takes allota oil, parts, and men and women to make run effectivly, let alone repair and retrieve damaged vehicles and put them back in the field. Another U.S. strong point, they refurbish and redeploy damaged Abrams and they can acuatlly ship via rail either to the manufacturer or another contracting company that specializes in refurbishing and plasma cutting, the rest in pretty much classified, as is many of today's most advanced tanks due to knowbody really knows what exactly goes into the armor on todays MBTs.
Also many of today's best tanks use German guns, the Germans make really good tank gun platforms and many countries, including the U.K. and the U.S. to name two major customers have used/ or are currently using German made guns.
The U.S. Abrams uses a smooth bore 120mm that is hand loaded, even when against an autoloading enemy the Abrams has proven effective due to it's ability to fire accuratly and due majorly to crew training.
Also onboard computers due help, esecially with navigation at night or in low visibility. Also using a hand loaded gun does cut down on maintence and the worse case scenario of having a jammed main weapon. It can happen in a tank as well, hand loading almost eliminates this problem, unless you are intoxicated, hence why this configuration is on some of today's and yesterday's most successful tanks.
Now, another great resource here would be to ask some the armor crewmen on the Milforum, they could probly give you a much much better insight on how modern armor is used and works on the modern battlefield.
And their knowledge and insight is just to good to pass up, drop one of the many crewman here your question because now I am even interested in finding an answer.
(If I really jacked some information here, let me know, also I am not claiming I have any experiance in amored combat or posing as If do in any way, I any inaccuracies are in my post please correct me)
Thanks,
Yo