Soakers do tend to fit a wider range of body types, although they do have limits on their stretchiness, especially in the legs. But the maker of each soaker should be able to tell you the sizing on the waist and on the legs, and you can measure your babe's (once s/he gets here) waist and thighs to check for proper sizing.
The other thing I've noticed about soaker fit is that if your babe's thighs are on the smaller side, the soaker will fit higher on the legs (sort of like underwear), while it will fit lower on the legs (sort of like boxer shorts) if your babe has chunkier thighs. Karen's daughter modeled my son's soaker and it was like boxer shorts on her, like undies on my son. Very versatile.
Karla
The other thing I've noticed about soaker fit is that if your babe's thighs are on the smaller side, the soaker will fit higher on the legs (sort of like underwear), while it will fit lower on the legs (sort of like boxer shorts) if your babe has chunkier thighs. Karen's daughter modeled my son's soaker and it was like boxer shorts on her, like undies on my son. Very versatile.
Karla