Claim #1- Can be applied in one brushstroke.
I have pretty narrow nail beds, so I was able to apply the polish in one brushstroke on most of my nails. My thumbs are too wide to comfortably do one brushstroke though. In the first set of pictures, I did apply the polish with one brushstroke. It was fine, but I really prefer the coverage of my usual three strokes.
Claim #2- Opaque in one coat.
This polish was pretty opaque in one coat. Not bad at all as you can see from the pictures. It does look a little thin with only one coat, but if you were in a real rush, I think this would be acceptable coverage. You can see how much better it looks with two coats in the second set of pictures.
Claim #3- Dries in one minute.
This is pretty accurate as well. The nails were dry to the touch in one minute. I probably wouldn't have gone running around touching things after just a minute. But good enough to gingerly get into your car and drive if you needed to run out to an event. When you add the second coat, the dries time increases a bit, but not too horribly.
So how do I feel about Sally Hansen's claims? Overall, if I were in a real rush, I would find the whole one brushstroke, one coat thing to be very useful. It would make my nails look presentable in a short time. However, for every day wear, I much prefer two coats, plus top coat, and my usual three stroke application, as seen in the pictures below. You can see in the above picture how much richer the polish looks with two coats. And even with two coats, the drying time was pretty fast, so this still makes for a quick mani. I think this color is really gorgeous too! However, as you can imagine, your results will vary with the color you choose. Light colors will be harder to get even and opaque in only one coat. But if you haven't tried the Insta-Dri series, they're available in a wide array of colors to suit every taste, so give one a try!
Sally Hansen Insta-Dri polishes are available at drugstores and your local Stop and Shop.