I bought a pair of Spanx back in June to wear to a wedding.  While I suspected that they wouldn't last for years, I expected I'd get at least 6 months to a years worth of wear out of them.  However,when I returned to work in July, I started wearing them 4-5 days a week.  Within a week, it was starting to develop holes in the seams.  After about 4 weeks, the holes were so big, they rendered the Spanx unwearable.  Enter the Profiles!  They're basically built the same way as Spanx, but without that weird hole in the crotch.  I have been wearing them at least 4 days a week for over a month now and they look almost as good as they did the day they arrived!  They have that stay-put elastic at the waist and it works really well.  It rarely rolls anywhere, never mind all the way down.  Best part is that the high waist means no muffin tops!

Some negative points.  The high waist is really high--and if you have a short torso or just hate having nylon all the way up, this might annoy you.  However I loved it.  The only thing that needs improvement is with the legs.  For one, they're very long.  Another poster mentioned that they were like bike shorts.  Yes, it's annoying, but I typically wore these with pants or with skirts that were at least knee-length so I never had a problem with this.  One way to mitigate this somewhat is to hike some of the leg up around the upper thigh to make them fall a few more inches above the knee.  The other negative is that the legs don't have the stay-put elastic around the lower part of the legs, so they do tend to roll; especially if you are hiking the legs up to make them shorter.  I tried to combat this by wearing them under my nylons, which kept the rolling to a minimum.

Overall, these are totally worth the price.  Don't expect them to last forever, like your traditional shapewear (they're basically like the tops of very high quality control top pantyhose).  But I imagine I'll get another month's worth of use out of them before I'll need a replacement.