That was the first type of feeder I used. Some bees will drown under the floats. The bees will propolize/wax the floats to the sides and ends of the feeder when empty, and small hive beetles will gather under the floats when sugar water has been emptied. Since bees have open access to the feeder, you will probably need to have a veil on and smoker going to add feed. You will also have the joy of trying to chase bees out of the feeder to add syrup if the hive is strong.
On the good side, you can put dry pollen substitute on one side and syrup on the other if you want, and bees can chase ants out if they decide to make a meal of sugar syrup. I rarely use the ones I have.