We've tried several styles of feeders, always looking for something easier to clean. Because of the sugar in the water and the occasional creepy crawly that gets in and drowns, feeders often get what looks like a dark colored mold and floating scummy stuff if you don't clean them regularly. Bottles with narrow necks were always a problem as were bases that you could not take apart easily to clean.
This year we tried these new feeders that are saucer shaped--the Perky Pet Hummingbird Oasis. Those have proven super easy to clean because the top just lifts off, you scrub out the insides, refill it, pop the top back on and hang it up. There are a couple of little irritations, however. The ant moat on the top has to be refilled 2 or 3 times a day because it dries out so fast--but then of course here in New Mexico, the humidity is usually in the single digits--very dry, with intense sun and frequent wind. I've also seen other birds sitting on top of the feeder drinking out of the ant moat. So if I am not diligent about refilling it during the day, I have ants in the sugar water at day’s end. It also hangs crooked. Try as I might, I cannot get it to hang level, so one side gets empty faster than the other side. However, I do like the easy-to-clean feature.
I tried putting Vaseline on the hanger to deter ants, but that hasn't worked so far. I guess when it comes to hummingbird feeders, there is no perfect answer. I was thinking of trying a larger ant moat, like the Trap It Ant Moat. If you have a solution, please leave it in the comments below!!