You kids are spoiled rotten today!!
I recall when the only "common" T55 kit was the original Tamiya kit of the 60's with motorization and REAL rubber tracks.
When the Danish-molded Lindy T55/Tiran kit hit, it was so badly wanted by all that was deemed Squadron Shop's Kit of the Year. At the time it was nirvana for Soviet armor fans. Then the ESCI T-series kits popped out.
These kits still have a purpose: if you were building a battlefield dio of a T5x wreck, don't waste Tamiya money on a "wreck" when you can destroy a Lindy or ESCI/Italeri T-5x for the dio.