Well after another few times cleaning out the 360, I just have to say I really like it. It's easy enough to clean but I have no comparison. The only thing is that if you tighten the cone too much it's really hard to open again so I just keep it halfway locked. The reasons I love the 360 are that Beau likes the water action and it's great for multiple cat use, even though I only have Beau, but I can imagine 2 or more cats drinking from the spouts easily at the same time. You don't even have to have it placed in an open area for more access room. I place mine next to a wall and there's still plenty of room around to approach from.
It is pretty loud though, if you're not used to the sound of little streams of running water in the house. I don't mind it all. It is a bit big though, but maybe once Beau gets bigger it won't be so noticeable. I bought 2 waterproof cat place mats to put under it that work great to absorb any splashes (Beau's gotten better with playing with it now, but he still likes to swipe at the water with his paws).
The other thing is finding the filters for it. I couldn't find any the last time I went to PetSmart, so I have to keep looking or buy online. I could always just not use a filter-- it'll still work as a fountain, but what's the point of that, right?
I don't know if all that info helped or not. Do you know if Ally and Ollie like more actively running water (the Drinkwells are better for this) or if they are fine with just a little bit of moving water (the CatIts and the Petmate)? I know the CatIt small fountain was quiet, pump-wise and water streaming-wise. I saw one video review that showed the FreshFlow having a loud pump, but I'm sure the way the water streams down it shouldn't be loud in that respect.
As for water capacity, I wouldn't worry too much either way since you WILL have to refill once or twice a week at least no matter the fountain. Well, I had to with the small CatIt and the 360 anyway, especially since I don't like letting the water get too close to the minimum fill lines. And you have the option of bigger reservoirs with the Drinkwell.
Also, with the 360, if you keep the flow turned to the slowest speed, it is not as loud because the water will stream down the sides of the cone at the bottom rather than dropping right into the water basin.