Okay, so I wanted to update with the results of an experiment I just performed:
I ordered an Alva diaper to test it out ($5! that's it!). It is much larger than my fuzzibunz one size elite, but it has more snaps, so you can make it small (not that any of us have teeny newborns anymore). The inside feels cheaper and thinner, but the outside PUL feels about the same as the fuzzibunz. The biggest difference is the insert. The FB insert is smaller, but made of "nicer" material. The FB also comes with 2 inserts, while the Alva only comes with one (larger) insert.
I decided to test their absorbency, so I came up with the following experiment: I submerged each diaper in water (no squeezing, just gentle submersion) for 60 seconds. Then I let it drip dry for 60 seconds. I then measured the water it held (by seeing how much water was left in the bowl).
Surprisingly, the Alva insert way outperformed, holding just over a cup of water, while the FB insert only held 2/3 cup! Now I feel more confident about ordering a larger stash - maybe 20 Alva - for when Armie grows out of the prefolds we are using now. I guess we can continue to use the prefolds as extra inserts for overnight. BTW the prefolds hold about 1 1/3 cups - and he can fill them to overflowing in about 6 hours.
When he does start sleeping through the night, will he pee less? Do I have a "heavy wetter" on my hands?