I had a pair of Zeal Polarized Photochromic Lens which I used for about 3 years. I loved them, they were fantastic in bright light and the transitioning could get quite dark in very sunny spring conditions and vary quite a bit in less bright conditions. Good clarity. However, for flat light not so good. I had another pair of Smith goggles that had a good flat light lens which I used. But my eyes are getting older and I don't do flat light that well, so others mileage may vary.
I suspect they are a bit oversold on the flat light bit, but they work very well for everything else.
I wouldn't trust any simulation for any lens or goggle lens from anybody. Color accuracy from any monitor is questionable. And since most of us haven't been on snow since April, I doubt if our memories are to be trusted either.
They will transition fairly quickly but be advised that ANY photochromic lens is temperature sensitive - the colder it is, the more slowly they will transition. Still a lot faster than changing your lens or goggle though.
I don't think of my Zeals as duds, they do certain things very well.
Unless you are buying online, go to a shop and try on a pair. Ask them to let you walk outside with them on.