In ascending order you would walk through Japanese, then Chinese, then Korean and Russian in terms of scarcity and value for US collectors
EDHREC lists it currently as the 36th most popular commander in the game
Its worth noting that these reprints include a healthy mix of merfolk-specific payoffs and generically good cards (Metallic Mimic, Thassa, God of the Sea)
When it comes into play, all creatures in play get -X/-X for the turn, with the X equaling what you put into the casting cost
The companions all have mono-color casting costs or are colorless, potentially adding a third color to your Commander deck as each of the Doctors has a dual-color casting cost
The Commander deck building tools space moves fast, and we're keeping up