I just finished a new sweater for my son. I used Knit Picks Brava Worsted acrylic yarn. I wanted to try acrylic for a large project like this and learned a great deal from it. I learned that acrylic doesn't hold its shape as well as wool. If feels heavier and it drapes longer than it measures. I had to rip out 6" from the bottom then add back the 2" ribbing for the bottom edge. Thankfully, my son was here for the fitting, so I knew it was going to be correct. The arms, thankfully, worked out well as I had him try it on. They ended up being about an inch shorter than when I made the same sweater out of worsted superwash merino wool.
While the yarn washed and dried nicely in machines and became softer, I ran into the same problem with yarn from Knit Picks as I have several times in the past. Out of the 10 balls of yarn I used, 8 of them had several breaks/joins in each. The joins were not well done and I had to unknit and rejoin them properly instead of just tying a knot as their yarn manufacturer does. I tried knitting it as it was but the knot usually ended up on the right side of the garment with a bit of a tail. Not good. I did complain to them and as they have done in the past, offered a credit or a refund , so that was good. This sort of thing has happened using expensive and inexpensive yarns, so it is a quality control issue that Knit Picks seems to be experiencing.
My son loves the sweater and it will keep him nice and warm during this cold Chicago weather.