I work all day so Izzy is in her x-pen which I line in one corner with pee-pads - no way is she going to hold it in all day so she is trained to go on the pee-pads. I like the x-pen since it's big and she has one end for pee-pads and one end that has her little housebed and food/water/toys. I like the x-pen since it gives her more room to exercise all day vs. the small sleep crate.
However she also has her sleep crate which she sleeps in at night or she goes in when we are only gone for a few hours like out to a movie/dinner/etc., Also - Izzy gets fed in her sleep crate so it's like her special home.....I have to feed her in there since I have 3 cats and she would prefer the kitty food vs. her own.