while buying robot, think about your pool drains. Most of them are stuck in there.
That is not really true... "some" of them do, but "most" do not.. It really depends on many factors, such as the type of cleaner, the type of drain cover, how they plastered the pool near the drain, and even how old and worn the drive tracks are..
I actually have four robots and out of the bunch only one has a habit of sticking on the main drain. The other three have never been stuck. I use the sticky one as my spare..