I bought these primarily for driving - I'd previously used a pair with amber Cat1 lenses (amber lenses are ideal for driving because they enhance contrast), which were great for weak sunlight, but not really dark enough for very bright days. Cat2 or 3 lenses are fine on bright days, but you need to remove them if it gets darker (or you drive through a tunnel etc.). In theory these photochromatic lenses should be the best of both worlds - amber Cat1 when it's gloomy, through to amber / grey Cat3 when it's bright.
So the important question is do they work? Thankfully the answer is a resounding 'yes'. I've just come back from a weekend's sailing trip, and they literally did not leave my face from the time we left the marina to the time we moored-up each day, and that included a mix of bright sunshine, overcast conditions, and going from bright sunshine outdoors into the gloom of the cabin. Five stars for the lenses, no question. I've only given four stars overall, because whilst the frames do the job perfectly well, they feel a little bit flimsy and creak a bit if you flex them. They're also a bit tricky to clean, because the nose piece obstructs part of the lens. They're by no means substandard - it's just that I've had sturdier-feeling frames at a similar price in the past. I might increase my score to five stars if they're still going strong after a hard summer's use.