Do the one-size fit like Blueberries? I have one Blueberry and it is so bulky on DD that she can only wear it with pjs. It is by FAR my largest diaper. I've heard such great things about the Swaddlebees, but if they're going to fit like that on DD, I'll pass.
OR
Is it the sized ones everyone loves?
Re: Swaddlebees?
Swaddlebees Econappi pockets fit similarly to the Blueberry pockets on my DD. They are OS. They were bulky on her until she got a bit older than your LO. (ETA - maybe around 6 or 8 months; now they're not bulky at all on her, but I also have Blueberry bamboo inserts. If you have MF inserts they'll be more bulky).
Swaddlebees Simplex are AIOs. They come in OS and sized. I only have OS, but it's very trim. I think the sized are even trimmer, but I'm not a fan of side snaps.
MMC 2.12.11 @ 8w
PVM 5.8.12
GWM 3.17.15
RPM 2.21.19