Yes, I have a handful of them which I've collected over the years. I have two black cardigans with shawl neck collars -- one is a thin knit (added this year), the other more thick & chunky; a cream boyfriend merino; and a black ribbed knit. I love wearing them over dresses, or over skinny jeans, and at this time of year, they work as outerwear. In the winter they work under 3/4 length coats. I have on occasion been known to layer a shorter leather jacket over them -- just to be different (I think I got that idea from someone here on YLF!)
I find them very cozy and warm, like wearing a blanket, and as such great for business travel when you don't know how cold it'll be on the plane, or in the conference room.
All of mine are petite so they are proportioned for my size. I don't belt in general and though that could be a cute look, I prefer leaving them open and creating a long lean line. For some reason I think this gives me the illusion of slimming & height. For some reason I have it in my head that I can get away with dramatic shawl collars (which I love but don't necessarily love me back), provided the sweater is long enough.
As for frumpy & matronly -- it is a risk. Choose carefully. I don't think any of mine are frumpy or matronly, though the cream BF one does have an ironic bit of "grandpa" going on, which I kind of like.
Fit tips: look for styles that have very fitted sleeves, to provide structure. Loose sleeves quickly look frumpy. I do in general also prefer higher cut armholes, but I would definitely try a looser, deeper cut or dolman or sleeveless/vest style this year.
I'd love to add a cocoon style this year!
