Pros: big enough for multiple cats, keeps water cold, easy to clean - only three parts, runs quietly, cats drink out of it a lot
I couldn't find the Big Max on this review site, so I'm putting my review with the Raindrop design.
After using other cat fountains, like the Drinkwell and Petmate line of water fountains, I turned to the Pioneer Pet Big Max Stainless Steel water fountain. They absolutely loved it! They love the water bubbling up from the pump and licking the side where the water flows. They also drink from the bowl. The stainless steel keeps the water cold, which is nice. Before I had plastic ones and kept putting ice in the bowl. It's easy to clean - there are only three parts: the basin, the top part, and the filter/pump. There is no slime like the Drinkwell 360. It is very quiet; I hardly notice it's here! The fountain itself is actually pretty big, bigger than the Raindrop design. It's a nice size for three cats. There are also instructions on how to clean the pump on YouTube.
My cat has a history of urinary obstructions, so this water fountain was the best pick for his health. He drinks out of it all the time, which is very important to flush out the crystals in his bladder.
Bottom line, get this!