Well, coming from Canada I've used dado blades quite a lot on my table saw and I don't find them fiddly, particularly dangerous, or any of that. I've got a couple of sets - a Freud that came with my latest saw (looks like it was imported), and the S&S set. Both are great, both are just accessories.
I like using dados when I'm knocking up a carcass out of MDF (dust collection... oh lord you need dust collection) because it's quick and very easy to be accurate. But 'quick' is relative. If I'm putting in a single dado pair, I'll do it by hand because it's quicker then setting up the blade. If I'm doing more then that I'll get out the dado set. If you're just starting to use one for the first time, you'll take a lot more time to dial in the fit. Since I tend to use them with MDF more then anything else, I keep a little chart with which blades and which spacers I've used in the past with which thickness of MDF. You can just take a minute to do the math each time of course, but I found that numbering the blades and spacers you have and keeping track of which ones go with which thicknesses of MDF saves me from doing any more then a single test-fit cut.
I didn't even need that back in Canada, but the weird thing is that the MDF I buy here isn't always the exact same thickness. Took a little getting used to.
There's always a lively discussion about North American table saw usage vs European when the topic comes up. I will say that in most places in the US and in Canada, you learn how to use a table saw safely in high school shop class. If your first introduction to a table saw is TV or the internet, you're at something of a disadvantage... and YouTube isn't a great place to go for safety tips for any kind of tool (though there are great channels out there that are the exception.).
If you understand kickback and how it can happen, if you understand that guards should not be removed for any cut other then ones that specifically require it, if you know where to stand and how to feed material into the saw, and if you know that all the safety features in the world won't save you from carelessness, then you should be fine to use a dado blade. There's a lot more to learn about table saws then just what I've written, but If you don't know the things above you're not ready to put any sort of blade on your table saw.
That adjustable groover set looks pretty darned cool though. I normally wouldn't casually put a tool made for one machine into another one, but the specs on that seem solid. If that works as well as it looks like it does, it would certainly be a much better approach then a traditional dado set. If they made one that went from 6mm to 19mm it would be just about perfect.
dak.