A little off topic, but why is it the better tracker?
I've seen other people say mediacreate is the superior tracker (though in some cases people might be joking/trolling and saying whichever tracker makes their favorite system/game look better is superior...).
Nintendo uses Media Create for all of their Japanese sales tracking needs, so that's usually the main justification. Other companies like Capcom prefer Famitsu for public sales reporting to investors...but they tend to subscribe to both services.
The two both have their strengths.
On the one hand, Nintendo, Sony, Microsoft, Square Enix, Capcom, Konami, Bandai Namco, Sega, and Electronic Arts all subscribe to Media Create.
But on the other hand, Famitsu has a special partnership with NPD and GfK and is internationally recognised by multiple agencies as the standard for Japanese sales tracking.
In my opinion...
Famitsu tracks ~3,600 stores in Japan, and they have tracked the video game industry for a longer period than Media Create, so you have more sales data to compare. And, we have more Famitsu data on GAF that we can use in sales threads.
Like Famitsu, Media Create tracks >3,000 stores, and they do a good job tracking the industry, but in my opinion they're a little too optimistic at times...so I prefer Famitsu.
You can't go wrong with either tracker, though.