From a maintainers view, skids - very little maintenance required but a bugger to tow the aircraft. Wheels - easy to tow aircraft but a lot of maintenance required! Just reading the responses so far and maintaining that perfect strut pressure can take a lot of effort. Dealing with punctures in the field can be fun. Replacing tail wheel lock pins because the pilot forgot to unlock during taxi can be stressful. Bleeding breaks, servicing struts, and pumping up tyres - boring. Undercarriage retraction and emergency blown down tests - exciting. Mixing up the pressure line for the brake and undercarriage jack on a Sea King sponson - spectacular!