I haven't tried the new formulation yet, so can't comment on just how long an open working period you do have before the paint starts to dry, but obviously climate and temperature will have an impact. I already find myself impatient with "regular" acrylic paint drying too slowly on cold days, but can see that an extended working period could be fabulous for painting a seascape on location on a sunny day.
Artist Robert Bissett has tested some advance samples and shares his thoughts on the Painting Forum, saying: "So far my impression is positive. It really does stay open longer. If the paint on your palette is 1/16" thick or more it will take a long time to dry. At least overnight! I did a plein air in summer temperatures and had little trouble adjusting. It's not like oils and it's not like other acrylics." It certainly sounds like it's going to be intriguing to try.
If the rapid drying time of acrylics is one of the things you enjoy about the paint, be sure you don't pick up one with the word "Open" on the label when you buy a tube of Golden once they go on sale! Don't be in a hurry and just grab the first container of Golden you see in the right color ... these days you've the choice of matt finish, fluid, heavy body, and soon extended working time versions too.
Assessing a New Brand of Acrylic Paint
My Best Brands of Acrylic
Image: © Golden Artist Colors