It really holds up well and the battery life seems quite impressive. I suppose that is also due to the few key features it is able to do. The car finder is one of my favorite features as it can be difficult to remember things when you have kids. Like, you know, your name or what day of the week it is. ;)
Its not a huge issue for me, but I have read that people prefer a smaller button on the device as well as something other than a USB charger. To me neither are a huge drawback. I like the simplicity of this product.