There is not much difference between using a single head with 3 knives and 6 knives. Multi-head razors come from Europe, where people have a lot of beards, so they need multi-head razors. Asia has never been suitable for multi-head razors, and the market has developed in recent years. Many people think that multi-head razors will be high-end, but this is not the case! Generally, both ends are ok! In addition to the high price of multi-head razors, the cost of subsequent parts replacement is also relatively high, and the endurance is also relatively poor, because it needs to provide power for multi-head blades!
I hope my answer can help you!