I used these as a backup for the first and second day of my period in conjunction with a pad before I summoned the courage to lean into the padless life for the remainder of my period.
I also bought the classic full brief for my lighter days, and both the seamless and classic are reasonably high waisted (sitting somewhere about my belly button) which I prefer in my underwear.
Absolutely love these; there's an adjustment period but it's very brief. You almost forget that panic of bleeding freely into the underwear because these work. No leaking! No fear of blood seeping through to your blue jeans! A gloriously peaceful night knowing you won't utterly ruin your pyjamas while you sleep!
They are a little pricey but when weighing that up against years of buying pads every month, it's almost a bargain. I'm definitely going to buy more in the future, these are going to change my life.