Which "Toto" fill valve are you describing? If you mean the TSU99A.X Universal Toto Replacement Fill Valve, it is essentially the same as the Korky 528MP, and the wear parts (i.e. the parts that wear out eventually) are absolutely 100-percent identical. Both are made by Korky. The Toto valve comes with a gizmo that allows you to set the refill level properly without flushing the toilet a few times, as required by the methodology used to set the Korky. That's the only practical difference.
The design of one over the other isn't going to make one wear out faster than the other. If people are actually experiencing faster wear out of one over the other, it's going to be based on sample differences, the conditions the valve is experiencing (i.e. usage, water pressure in the house, etc.), etc. But most likely these are merely perceptions by the owner rather than actual experience data.
Regardless, they are both good valves, because they are essentially the same valve, and the 528MP with the silver cap is going to be a little less expensive than the Toto valve.
So flip a coin and pick one. They are both excellent and easy to install in your Toto. Be sure to look at the installation video for the 528MP Maxperformance fill valve on the Korky web site. (Versions other than the 528MP don't have an adjustable refill percentage, and are therefore not optimal for your Toto.)