I bottle condition and seem to have low carbonation in most beers. Except my Hop bombs! I use 500ml PET bottles and just feel them for pressure as a test.
How long do you all leave bottles at cellar temps to properly carbonate?
Most get hard in 7-10 days. But when opened, they are often weak, pouring with 1/2 inch of foam, or less, which dissapears quickly.
Retention is another issue, tied to other things, like aplha acids, protein, clean class, etc...

