It's clear to me now that Rain-X is one of those love it or hate it products.
For every person I have talked to who likes Rain-X I've talked to 10 who think it's one of the most worthless products on the market. It works as advertised under such a limited number of situations--- can't use your wipers--ever, increases glare at night, won't bead off light mist, etc. etc. etc.--- that it's simply not worth the effort. Either that or you have to keep applying it on an almost continuous basis.
I've tried it off and on for decades on vehicles and boats. I guess in the hope that "this time it will work." It never does and our damp, misty, rainy climate here forces you to negate it's effectiveness almost immediately. I know people who have told me that "they use Rain-X so I never have to use my wipers." On occasion they have followed me in their cars to go somewhere. If it's raining, guess what? Their wipers are always on, just like mine.
Perhaps in a drier climate where it doesn't rain much and when it does it's hard, Rain-X might be worthwhile. But it's a total waste of time and money up here, at least in my and most everyone else I know's experience.
And it's not operator error. I've followed the directions to the letter. I've buffed it out multiple times with things ranging from soft cloth diapers to electric buffers. Nothing makes any difference.
So if it works for you, great, keep using it. But if you've never tried it and want to, don't be surprised--- depending on the conditions under which you operate--- if it fails miserably and makes things worse than they were before.
I'm 100% with Walt. Our boat has great wipers. They work with fine mist, heavy spray, and everything in between. When they are operating we get a clear view forward, not a view through glass speckled with beaded drops or streaked with countless rivulets of water running down the glass. We never have a problem seeing debris in the water or little things like crab pot floats. And the effort to get this great view forward involves pulling a knob.