Brian,
I dont like the feeders you are talking about. I have seen weak hives get flooded with using them
I prefer the rapid feeder (with the internal cone and cover on top of it so the bees dont drown)
Just open the feed hole in the crown board and place it on top, and feed (and refill) away. It is up to the bees to draw it down as they see fit. It is a noninvasive way of feeding them.
I know this is not the answer to the question you asked but if you are going to spend a few bob on feeders, spend it on one of these.
Best of luck with what ever road you take.