I had M60's and traded them for 100's. The difference is substantial across the entire spectrum, but esp. in the lower end. They have breathed new life into some pretty old and crappy recordings. Newer recordings will lay you out flat. The guilt over buying them was quickly eradicated by oodles of satisfaction. They have become my favorite inanimate objects, next to Hello Kitty.

Always call the place you live a house. When you're old, everyone else will call it a home.