i dont because i prefer to go straight into square 4 litre pots,, ganja does seem to like being repotted in stages and quite often wont root out as well if put straight into a main pot like a 15 litre for example,, but i find does just as well starting in a 4 litre and going up to a 10-15 litre,, just my opinion,,,
Plant into a transparent cup, and stack that cup into an opaque cup (add drainage holes). Allows you to see the progress of your roots.. never get rootbound.
Keep it coming guys... If you had to estimate how many growers use these cups in the world we live in, how many, what percentage would be using them? Guess?