I have had this for less than a month and have used it to cook a roast, a couple of cups of rice, a pound of lentils, and other vegetables. It has worked almost flawlessly-- the little popup was initially stuck the second time I used it (after the rice). After 10 min I touched it just to see what was going and it immediately popped up. Since then I make sure to rinse things well after each use, especially underneath the handle, and it has worked fine.
This is the first pressure cooker that I have owned and it's been very easy to use. The instructions and cooking guides that are included are very helpful.