I haven't seen the TakaraTomy one in-hand, but the colour scheme, while faithful, looks kind of plain.
I do like the Amazon Unicron's paint scheme. It works well.
My only complaint is that the primary peg for Kranix is poorly molded so Kranix just spins loosely around on it and falls off if Unicron is tilted. I don't know if this is a defect common to all Unicrons or just mine.