I switched from tampons to flex discs probably 6 months ago give or take. I don't even know if I can call it comfortable because I cannot feel it AT ALL ( to the point that my first period trying them I freaked out when I had realized I completelyforgot it was in). I have a pretty heavy flow and I have had no issues with the 12 hour wear. I usually ensure it's popped in place anytime I use the restroom, for the most part it stays where it's meant to while using the restroom. I have also tested the period sex claim, neither my partner or I felt it at all and there was no leakage. I still cannot wrap my head around the semantics for period sex, but hey it all worked out! It is a little messy removal wise but not enough to deter me. I am extremely happy I made the switch. I am no longer constantly worrying about leaks or changing tampons or what the chemicals are doing to my body. If you're on the fence about trying it, just do it! Yes, the cost is a little bit higher than tampons but a box of disc's honestly lasts longer since there is more time between when it has to be changed out, better "absorbancy" and so on and so forth. 100000% recommend.