Numismatic gold coins are often very beautiful and there's always the historic aspect to it, so if you're in for creating a numismatic coin collection, then those coins are a very fine addition.
However, in many cases, numismatic gold coins can only be bought well over the spot price of the actual gold. So if you're investing in gold purely to have a financial backup, then you'll probably drive better buying bullion coins or bars. Just keep an eye on the premiums.
Then again, there are coins (such as the 20 swiss franc gold "vreneli", as you showed in your video), which can be bought from banks (in Switzerland) at close to spot price - the same probably goes for official gold coins from other countries, you can probably buy them from banks of the respective country. And in some cases, retailers also offer some numismatic gold coins at bank prices (but no high quality of the coin guaranteed).
Lately I've preferred to stack bullion coins, and sometimes Vrenelis (since they're often sold close to spot price) when I want something more historical. But to each his own.