The best part about the internet is we can defiantly disagree with each other and it's all good.
Using a cheapo welder is one thing, but you only get ONE set of eye's, and some people don't even get that. I've been messing around with welders long enough to know better and cheap junk helmets are just that, cheap junk helmets.
On the hobbyist level, someone may try spotting in a new fender, or some other "thin metal" project that requires constantly triggering the gun, doing one small tack, moving a bit, doing another tack, and so on. This is how you avoid warping the new metal. Doing a regular fender job and one may trigger the gun 500+ times, that's 500+ changovers for the helmet at 1:25000th of a second(and that's a good helmet). It doesn't seem like much to type it here, but it adds up and the UV's WILL HARM YOUR EYE'S eventually.
I use an Optrel helmet for mig that works real nice, but was pricey, but I only use it once and a while now. My favorite (and cheap I might add. $90) is my Accu-strike. It's a mechanical pop-up shade that you move with a slight movement of your chin. The learning curve takes a couple hours of messing with it, but after that it's like riding a bike. You lower your chin about a 1/2" and the shade lift's to give you that peek to setup in your weld area, then the shade drops right back down when you raise your chin. If you want to do some grinding, you open your mouth a little more(like 1") and the shade goes all the way up and locks in the up position, and the helmet has a nice large CLEAR safety glass for grinding, etc. When your ready to weld again, a quick nod, and the shade drops right back down and your ready to go.
In my opinion, having the shade in place way before the arc strike is a huge benefit.
Google up "Accu-strike", there's all sorts of vids on the internet of people using them.