Winsor & Newton hasn't simply changed the packaging on their existing artist's grade acrylic paint (Finity brand), it's been reinvented and is an upgraded product (now called W&N Artists' Acrylic). I think the two most significant changes are the longer opening time (up to 20 to 30 minutes, depending on how hot and dry your studio is) and the lack of color shift from wet to dry paint.
W&N has long been one of my favorite brands of acrylic for the balance between quality, availability, and price. I've enjoyed using this new version even more for its slightly longer working time.
Pros
Cons
I haven't timed it to see exactly how long this acrylic paint stays workable, but it's definitely longer than average. (W&N say 20% longer, or 20 to 30 minutes.) When using it on canvas, I've found it gives lots of time to blend and manipulate the paint but not so much I'm twiddling my thumbs waiting for the entire painting to dry. When working on unprimed paper it dries far more rapidly, but you'd expect that as the paper sucks up moisture.
W&N say the new clear binder eliminates any color shift from wet color to dry, and certainly, I can't see any. The wet color I mixed was what I had when it dried. Color shift with acrylics has never been a huge issue for me because I've learned to accommodate it or wait a little while until the paint was dry to judge. But with this paint, it's simply not a concern at all, which will make life much easier for new acrylic users.
The colors are gloriously saturated; strong and intense. The consistency is soft buttery, so it holds brushmarks well but also spreads and mixes easily. I expected to like the paint because I like the previous Finity version. What I hadn't expected was just how nice the extended working time is.
It's short enough to fit my natural impatience for things to dry when glazing if I divide a canvas into a few sections and rotate working through these. It eliminates the hassle of using retarder or spray-on water, reduces the stress of having to blend immediately but doesn't give so much working time I'm going to muddy things up by fiddling too much. With the intensity and choice of colors and this working time, it's a paint I'm sure I'm going to be using a lot.