My five cents - I prefer wheels. Better on rocky ground, and allow flexibility for running landings when OEI. The tailwheel config is the only config I have been exposed to, but it is great for fast approach and landing using aerodynamic braking with the tailwheel pinned (mil tac ops). Oleos with a long stroke can absorb vertical impacts and help save your back at the bottom of an auto. I suppose skids are a fair bit lighter though, which is better for smaller helicopters.