I'm so glad someone is talking about this. I fly United Business Class where the configuration is usually 2-1-2 in a 767. They are now upgrading their aircraft to the business suites where every seat is on an aisle. This eliminates the need to step over your fellow passenger. About one year ago I was seated at my favorite window seat and had to go to the Lav. I didn't want to wake up my neighbor, so I stepped over his flat bed and did my business. After landing and checking into my hotel in London, I started having lower back pain. I had aggravated my herniated L-4, and spent the next 3 days in my room. Now I always take the aisle seat.