I've not tried the wifi since downloading Zelda (4 hours for 13gb!), but I did find that balancing the Switch on top of the router doubled download speeds. Also the wifi on it doesn't work at all unless I have the joycons attached, which suggests that the bandwidth the joycons use is the same as the 2.4ghz wifi band and is perhaps interfering. Sadly my shitty Sky router doesn't have 5ghz, but to be honest I have no intentions of using the Switch online for anything other than patches and system updates. The only reason I downloaded Zelda is because the physical copy wasn't available anywhere.
Putting the wifi aside, after a full weekend using the Switch I am highly impressed with it. Zelda is superb, but simply using the Switch in all its modes is a real treat and the core concept of it being a console that you can pick up and keep using wherever you go is 100% proven for me. I've been playing it over lunch at work and it's just as good as playing it on the sofa at home - that in itself is already worth the asking price.
I'm finding the joycons are great to use when attached to the sides and also with the grip, but are trickier to use loose in each hand because of the need to hold on to them while simultaneously moving my thumbs. Kind of hard to explain, but my hands are big enough that gripping the joycons without my thumbs means it's hard to accurately position my thumbs. Doesn't really matter though, because using the joycons attached to something is absolutely fine.
I love this console, to the point where I'm willing to overlook the slightly crazy pricing for now (not so much for the console, which to be honest I think is fair at £280, but for the games and accessories which vary between quite expensive and taking the piss). I'm trying to separate my thoughts about the console from my thoughts about Zelda, as that has undoubtedly made a big difference to my initial opinions. Aside from the wifi, I can't really fault it so far. If anyone's on the fence and can spare the money, I'd have no hesitation in recommending you take the plunge.
"This boy is depriving a village of an idiot."