My €.02 here… had a mate that played with T05-fx who changed to Rakza 7 Soft. He replaced his T05-fx, that had gone dull over a span of 2-3 months playing 10-15 hrs/week with Rakza 7 Soft mainly because he sought something familiar but even tamer. He's steadily (and rapidly) improving, and just replaced the Rakza 7 Soft with… Rakza 7 Soft, after 3-4 months.
In my recollection rubbers lasted longer; the replacement rate of the usual Sriver or Mark V rubber would be measured in years rather than months. But that was then, and this is now; I had to replace my (red) Rasant Grip too after a mere few months. My Vega Pro is still usable whereas the Rasant Grip just died.
Anecdotal, but to me T05-fx doesn't look durable. Regular T05 lasts longer, and people claim it's durable; my experiences were different, though.
Wouldn't it be nice if somebody actually measured rubber properties, and not just score them by subjective grading? Durability, grippiness, tackiness, speed may be tougher to measure than weight, sponge thickness and hardness, but I think I could devise a test methodology for it. I'm guessing there are no vested interests to sponsor such a fact-based approach, though. Shame.
