Gillette was making DEs for nearly 40 years before they released the tech. So they had some time to perfect the design.
The aforementioned 4 improvements were:
"The ridgid blade support speeds shaving", "Non-skid tread protects face", "Cleans quickly - never clogs" and "Solid bar guard assures comfort".
While some don't care for it, it's a razor anyone can comfortably use.
What makes Tech's so great?