Oh, right brain training is such a popular topic lately! From what I've heard, the two main names that come up are Heguru and Shichida, some mums swear by Heguru, saying their kids became noticeably more focused and had better memory recall, while a few others felt the teacher quality at certain centres wasn't quite worth the premium price. Cost-wise, you're looking at roughly $4,000 or more per year, so it's definitely not a small commitment. Someone in my mum chat group mentioned that Heguru sends kids home with materials to reinforce the learning, which helps stretch the value a bit. Honestly, the science behind right brain training is still debated, so I'd say go in with realistic expectations rather than treating it as a guaranteed edge, but 18 months is within the recommended window if you do decide to try it, so no harm going for a trial class first to see how your son responds before committing to a full year.