I'm gonna TMI a bit, but since you asked...
I bought a pair to try. My main issues that I hoped Thinx would help with were super flow days where I want a little backup to the tampon, the last taper off days to avoid wearing a pad or tampon, and most importantly nighttime. I wear a pad at night (paranoid about TSS and wearing tampons overnight), but no matter the length or wings I get leakage forward and back. I was hoping the Thinx would solve that. But on heavy nights I'll still need to wear a pad with the Thinx because I leaked through them in the "center." They'll be great for the last few days of my period definitely and as insurance against leaks on super heavy days. I find the pair I have, hiphuggers, very comfortable and better than a pad. I don't feel wet. I hand washed them and they dried in less than a day, so you wouldn't need one per day of you wash every day. They aren't frugal and reusable pads would be cheaper, so I haven't yet bought more pairs. Experimenting this week, so to speak...