The main disadvantage i've noticed is that during the winter the weather doesn't cooperate as much which prevents tbs from harvesting as frequently as they'd like to. This means - backorder. But in a way - this is almost kinda good because when *we* the aquarist think we're ready - waiting the extra time can't do anything but good for the tank. At least, this is the way I see it!
Hurrying can only lead to trouble right?
As for your question on the hitch-hikers, I have no clue. I'd assume there should be no difference.
Phil