I say its better to pot up at least 2 times for a few reasons. you can 1 see what your roots are lookin like, if they are nice and healthy or what not. 2 if you let em go in say a 5 gal pot you will be root bound by the time they are done veggin. so with smaller pots you can somewhat restrict growth and everytime you pot up they will expand. if your indoors i knwo a 5 gal pot isnt practical so a 2 or 3 gall should work its just up to what you have available for space. and what you want for your yeild. bigger pot = bigger plants and bigger buds.