Yes, but I only buy them in the sales when they are under £15. Still day light robbery and I only buy the patterned ones, not the plain opaque ones. Primark opaque holdy-inny tights are the best opaques ones by a mile. I have some that are 3 years old and still going strong (bit bobbly on the foot but fine with boots).
I recently read/saw something about tights - and Wolfords scored pretty low on durability and non-running. Which, considering the price you pay for them is a bit shit to say the least. Can't actually remember whether it was a magazine article or a current affairs lifestyle programme.
I like the M&S ones but make sure you get the right size or the waistband can be a bit tight...
Also like the M&S cashmere ones for vv cold days, They are really toasty. But they are not completely opaque and do have a wooly look about them so look a bit less dressy for work. I still wear them a lot but not when going to external/client meetings or trying to impress (an an in house lawyers so dress code is pretty flexible but sometimes have to tart up for the bigwigs). Great for weekends with boots, a warm coat and a lighter dress.
Re the Primark opauqes, you need the shaper ones. I like the tummy toner or bum shaper ones. They come up to my bra line and don't move an inch all day and do a good spanx style job. I really recommend them. They are also totally totally opaque. They also do a ribbed version as well, which are nice for a change. Have a good feel in the packages - you want ones that have a nice long body on them.
Wolford shiney ones are nice for a night out but are a bitch in shoes as they are tooo shiney and your feet slip all over the gaff.
Oh, I also like the M&S autograph 15 denier hold ups too, they do a nice pair of back seamed stocking style ones which are great for when you want to feel a bit more sexy than normal but don't want to flash a load of leg or tits. Plus if you rip one, you can keep the other one and buy a new pack!