After trying a few diapers out on First Daughter, we eventually filled out her stash with Knickernappies pocket diapers, which worked perfectly. So, when we needed a few for Second Daughter we bought the same thing. They did not work for Second Daughter. They leaked when she made a wet diaper. Every. Single. Time.
First I tried fixing them. I tried different inserts and combinations of inserts. I contacted Heather (who was very helpful) and even tried hand washing my diapers to rid them of any residues. Nothing worked. They simply didn't fit well enough around her thighs.
We tried a different pocket diaper, a Fuzzi Bunz One Size, because it looked cute and I couldn't resist. It seems to work just fine, no leaks at all. Personally, I don't think it's as easy to stuff as the Knickernappies (especially the new version!), but mostly we decided against them because we were afraid to buy another whole pile of pocket diapers when we were 100% sure the fitted diapers would be successful.
So we made an investment in a days' worth of fitted diapers to use with our trusty Thirsties covers. We have three or four different kinds of fitted diapers and they all work well with only minor differences in fit. The fitted diaper with a cover seems to create an incredible barrier that nothing has penetrated.
We're hoping Second Daughter's shape changes a little as she grows so she can wear all those large Knickernappies we have from First Daughter. In the meantime, she's still wearing them when we're home and frequent clothing changes don't matter so much. Though I wouldn't suggest investing in six diapers just as backup, it is nice to know I have lots of extra diapers and can easily go three days between washing!