I am also a Thinx devotee. I have never been able to get a tampon in without pain involved, so I am a life long pad user. And I always had to be careful about leakage — too many times I have gotten off a chair only to see red spots left behind.
I bought my first pair of Thinx two months ago and have had two periods since and I just love them. I did end up using a pad on my heaviest day, particularly because I only had the single pair of Thinx that had to be used for several days. I had a bit of bleed through but I think that was because I was wearing the same pair for too long, so I have ordered another one for next time, since the pair I have worked so well.