I have one cat who likes to graze and another that likes to eat everything in front of him as fast as possible, then vomit it up.
This feeder saves me so much time as I no longer have to monitor meal time, and my slow kitty is able to come and go without his brother stealing his food. Fast kitty was not a fan of this and tried to find a way around it several times, but has mostly given up now.
The lid closes fairly quickly when the cat pulls his head out. My only issue with the bowl is that it is slow to open for the first time after using the manual close button - in other words, I put the food in, close the lid manually and place the bowl on the floor. When kitty sticks his head in to open, the bowl is slow to respond the first time. After that, it opens more or less as soon as his head is over it.
My boy took a while to learn to use it, about two weeks before he seemed fully comfortable. He's not a smart cat, his faster brother understood the concept on day one. Due to the slowness of the first opening my slow boy has somehow decided that it opens when he purrs at it, which is very cute.
Overall, very impressed with the bowl and I think it's worth the money. It's also (at time of writing) cheaper than the other microchip feeder you can get, which has the added downside of being completely open at the back so another cat could stick his head in at the same time.