>>6747563Scale wise, it's difficult to say, because every form of media is so inconsistent with the size of the balls. They seem about accurate to what you see in the games though, which is to say they're probably a lot smaller than what you'd expect.
The Moncolle balls are closer to what you see in the anime, but are aimed at kids, so they're made out of cheaper materials and don't have the raised details on them (like the ridges on the greatball are just pained on with those versions). They are weighted to keep them upright though, which is a nice little gimmick feature, plus they're much easier to get a hold of and really cheap.
They also just announced a Mettacolle version, which seems to be about the same size as the Bandai one, but is made out of metal. Hard to judge it until it's out though and it's unlikely we'll see them do more balls in that style. The description mentions some kind of interior.
There's also the foam ones they sell in the US and the play and catch versions, etc, but none of them are really worth considering. The Bandai ones are easily the highest quality ones we have at the moment. They have sculpted interiors, high quality paint and details, double as candy dispensers and include stands for displaying and clips for wearing them.