First thing to teach - go with what you want, not what the rest of the internet wants you to go with.

I go Japanese for most things because they put in a little bit extra for roughly the same (when you have to import both). However for the Combiners I have purchased Wave 1 and will purchase Wave 2 of the Hasbro versions because they are coming out so much quicker and I have been so "pumped" to get the toys.

I did the same in 2006 when Classics hit, as it was around 18 months before Japan released their versions

However, I don't go Japan only as Hasbro do release some toys that never see light in Japan so on the safe side, I have also been known to purchase Hasbro only to then sell Hasbro if Japan releases