Is this from experience or speculation? There are two reasons, imo, why the rc18 is more popular. One, Associated vehicles and parts are more widely available in the US. Two, the rc18 costs less. I don't know if you've noticed, but on this forum people are constantly making threads asking if a particular cheapo part or supply is "any good". So many people are looking for the absolute cheapest products they can get away with. The rc18 costs less than the m18 so, yeah, it's natural that more people are going to buy it. Plus, most RCers(at least in the US) are strictly bashers, so they don't need a super high performance car.