This is problem just personal preference but I found that with U ultra thins I just don't feel comfortable nor do they hold up for long.
Ok they are cute and the packaging is adorable for what it is, nicely brightly coloured. But what I have experienced from the range is that they don't hold up to women who have a highly than average flow. I went through the whole packet in a day!! normally a packet lasts me at least 2-3 days.
Its a hard thing to judge as I think that this brand and especially this level of protection would be ideally suited to the younger girls, the newbies to the period world, or for woman who have light short periods.
Firstly, I really like the packaging, it's fun and colourful, a real pick me up for those days you have a horrible cramp. I also like these pads a lot, I have medium flow so these ones are perfect for me. I like that they are thin and when I wear them, I don't even realise. I have tried libra ultra thins, but for me, U by kotex ones just feel much more comfortable and suit me more. Absolutely love them. However, if you have heavier flow, then these ones might not be so good, and you may have to invest in the super ones.