I hate when the keys have a huge gap between them.
People say that a lot about chiclet keys, but if you look at your keyboard right now you will realize that your keys are not cubic in shape. They have a large beveled edge. The actual key surface size is the same, but instead of filling the gaps with beveled edges, they go straight down. The main difference is chiclet keyboards usually have less key travel. So if you are used to banging on a keyboard with huge travel your hands will tire out quickly, as you have to get used to the lighter touch.
Bought one of these for my desktop mainly because I want some extra desk space and I have an Anywhere mouse so I can use the unifying receiver without using an extra USB port.