I got my Problo as a Christmas present. I have lots and very long hair so I needed to purchase a few more of the medium and large size ones. Delivery was super fast!
As a working mum, with virtually zero time for myself, I found using the rollers tricky at first, however, as I used them more, the easier it got as I explored different ways to put them on.
Quick to cool down, and if they get tangled up, don't panic, just do a strand at a time.