I thought I would share my experience and why I ultimately am using cup waters. I originally bought nipple waters because they seemed to be the way to go as they are used quite extensively. The cup waters made more sense to me but they were more expensive and I saw more people using the nipples, both backyard flocks and commercial. However I have definitely changed my opinion. Nipples: I know many have no issue with the nipples, but I could not get them to stop leaking. I did not have them over pressurized, they were gravity fed (from not too high an elevation) I threaded them direct into PVC and initially had some of the threads leak, so I pulled them all and sealed with silicone. That sealed the threads but the nipple itself was also leaking. I made sure they were clean, still leaked, made sure they weren't at angles, still leaked. I'm confident the issue is that the pin does not come back to rest in the appropriate spot sometimes (big leak) and the sealing surface itself is not designed well enough (causing a small leak) that the weight of the pin can provide a seal. Also, once you put them in they are in, it's very hard to relocate move or service them. Also harder to teach the chickens to drink from them. Cups: I switched to the cup waters and found the design to be infinitely better. The sealing surface is actually an O ring that is around the yellow "lever", the yellow lever has a spring that keeps it extended out into the cup (pulling the O ring against the sealing surface, sealing the hole) this action insures no leakage. The Oring itself is a far better seating service than the nipples. The Oring is both larger, more malleable, and possibly held to the seating surface with the spring. The result is it takes larger particles to cause any leakage. This is VERY easy to service, worst case you have to replace the O ring. Even when the inside gets dirty you don't have to take it apart simply pushing the yellow lever in fully unseats the O ring and any dirt that was causing a drip gets flushed out. Even if you did have to take it apart it comes right out in 2 seconds top clean. Any action on the lever, up down left right or in, allows water to run and fill the cup. The chickens only need to see the water once and the rest is completely intuitive. Additionally, since you can (and probably should) supply them with water through flexible 1/4" tubing it is very easy to add or subtract cups or relocate them and work on them. Running the lines themselves is also far easier, no glue needed, no cutting really except 2 seconds with a pair of scissors or razor. You don't even have to measure really, just cut as you go. The one issue I have found is that gravity feeding them from only about a 2 foot height doesn't supply enough water pressure for my liking. IMO at that height (around 1psi) the cups fill too slowly. I would prefer that when the cup gets half empty and they hit the lever, it nearly fills back up again (at which point they wont hit it) as it stands now it has to get to only 1/2 to 1/4 full before they start activating the lever, and then it only gives them enough for a sip or two. Summary: Nipple pros: Cheap, (ideal if you need like 500 of them) Nipple cons: Leaky Harder to teach Harder to service/relocate/add or subtract. Cup pros: Don't leak Easy to teach Easy to service/relocate/add or subtract Cup cons: More expensive Requires considerable height for gravity feeding to fill, in my opinion, adequately. MAYBE dirtier, not in terms of poop, but it is a bowl so stuff can get in it like dust. Not really an issue when the entire thing is cycled each time they drink. I hope this helps those trying to decide between the two.