Love them! I have 6 pairs hehe. They can be very flattering on certain body types, especially dark blue ones.
The super skinny ones from Cotton On are awesome, lots of stretch and only $40. I reckon they fit better than my Sass & Bides and Tsubis which both set me back $200+ each.
Skinnys, band tee, cardy and flats is pretty much what I wear every day

ETA: my 57 yr old mum wears black ones sometimes, not the super skinny types just slim fitting but they look awesome on her, very slimming.