Just that really. We have had our lovely girls for 10 years and have always used cheap supermarket litter. They go outside so it's not the only place they toilet but we are now hitting the time of year where they stay inside more, especially now they are over 10. The smell isn't too much of a problem because I change it frequently and it's in the bathroom where the window is always cracked open. What is driving me batty though is the bits everywhere. It gets trodden all over the house, it's so messy. The litter tray is a covered one so it only comes out the entrance but it's stuck in their paws and we just find little white gritty pieces everywhere. I have always been reluctant to try more expensive types because I change it every few days so we get through it but maybe it will last longer and not be as bad as I think? Looking at wood pellets? Are they less messy?