Doesn't really deter circling roots. Mostly those grooves provide anchoring or "grip" for feeder roots to hold onto. I've got a few pots from older U.S. potters (Don Gold, etc.) that use this detail. There are some western bonsai books from the 90's that said such grooves were used in Japanese pots because the Japanese and Chinese said the details were added to give the roots "something to look at." Don Gould used wavy grooves on the sides in the shape of flowing water...From what I've seen in using the pots over the years, it mostly works, as at repotting time, I always find feeder roots "gripping" those grooves.
Pots without grooves can be a little more unstable as root masses can slip around, especially on porcelain, or other smoother finishes.