Just my $.02 -- having a top box is very handy. When I'm commuting, I put my lunch, laptop, and small gym bag with work clothes to change into when I get to the office. Helmet goes into the top box when I get to work. My bike had the full set of factory luggage and a tank bag when I bought it. When doing a long weekend, I can put clothes, extra pair of shoes, and a CPAP in the top box and carry snacks/drinks in the tank bag. I haven't had a need for my side cases yet, but when I take a longer trip or have to carry extra gear for camping, those will be helpful. Crosswinds are noticeable with the top box (and I have a front fork brace) so in my dream world, I would get a big ( > 60L) dry bag to strap to the tail and remove the top box, when going on a multi-day trip. Then if I still need more cargo capacity, use my side cases. I don't ride 2up, so I don't need to keep the pillion open either.