Im also researching. I feel that shichida is still much more established and heguru is more expensive. both dont have trial so u must make sure u choose e right one... There are also my lil genius, igenius, neuro tree...etc keep an open mind, go for their trial lessons and decide thereafter...
Find reviews here: https://community.theasianparent.com/q/shichida-heguru-better/24805
Go with the flow. Depends on many factors - e.g. cost, location etc