I seldom upgrade, but when booking the flight I look at difference between economy and business and when the difference is the right balace between comfort and price, I book business. As a non-status passenger I value priority check-in and security and lounge access. It saves a lot of time at check-in. I do travel with suitcases and two pieces of handluggage, so flying business is a lot less hassle. Being elderly I do like some more comfort.