I have not seen it posted anywhere, but Modelflex seems to have reformulated their products. I recently bought several of their latest batch. Here is what I found:
1. The paint it much thicker than before. It needs a 4-paint, 3-Tamiya thinner reduction for gravity fed airbrushes at 27 PSI. I also used 8 drops of paint retarder.
2. Pigment grain seems to be much smaller with more bulk going to the carrier. The end result is a VERY thin surface, even in areas you think were too thick.
3. Paint dries to a medium-high gloss much like the old Accu-Paint. In fact, after thinning, the paint feels and acts like Accu-Paint, only with water clean up and no odor.
4. Color profiles have changed a bit. The Conrail blue shifted a half shade to yellow/green and a touch darker. Its not inaccurate, but may not chip-match previous paint jobs.
Overall I am pretty impressed with the formula. If you were unhappy with Modelflex before, I suggest you give it a try. Especially if you are an old Accu-Paint fan. It's now one of the cheaper paints out there and paints much nicer than Testor's Acryl.