I think ALL feeder suck. Some more than others.
Top feeder advantages (assuming a screened in access area):
Feed without even suiting up.
Feed without opening the hive.
Feed a lot at a time so you don't have to feed as often.
Disadvantages to a top feeder:
They won't take it when it's at all cold. In times where a baggie feeder or a jar over the cluster will be taken, they won't make the trip up and over to get that cold syrup. This happens even when it's quite warm in the daytime if it gets cold at night. For instance if it's in the 30s at night and the 70s in the day they usually won't touch the top feeder where they will suck down the syrup from a baggie feeder, a frame feeder, a jar or bucket over the cluster or a bottom board feeder.
If there is a space for one bee to get in the top cover the feeder will get filled with drowned bees.
You have to remove it to work the hive and if it's full this is VERY awkward. When queen rearing feeding is a very useful tool just before giving cells to cell starters and just before introducing cells to mating nucs. With a top feeder you have to remove the feeder to get to the hive to do your manipulations.