Because they are so dense, they're warm (relatively speaking, even in 20 degree Midwestern weather) and they really are a great control top! I would recommend these to anyone, no matter the age. They also don't bunch up like some tights do at the ankles.
I really like these tights. They are substantial but not too heavy. They will definitely keep my legs warm without being wooly. They don't have as much of a control effect as Spanx, however. Very comfortable.
They are truly, "Super Opaque!" So many tights claim this, and end up looking see-through. My recommendation would be if you are on the cusp of sizes to go up, that way they don't stretch thin anywhere. I plan on getting another pair or two of these!