I went up one size in order to achieve the big and baggy look presented in the pictures, and it was the right move. (XL instead of M-L, depending on make or style)
The sweater looks great on, perfect for any age group. I bought 2 additional ones as gifts for my dada daughters ' one in her late twenties, the other in her earlier thirties. Both loved it as much as I do.
It's comfortable and, I believe, will wear and wash well.