Well, it was a toss up. Insurance covered 1 side due to it being a claim from Hurricane Sandy. So I just had to do 2 sides & the shed. I've lived in a tanish colored house my entire life. People always go with tan or beige, or other weak ass neutral colors. I was just tired of it and wanted something new. My wife and I had bitched about the siding pretty much the entire time we lived there with the eventual goal of replacing it just to make the house look nicer.
So we settled on a color and absorbed the rest of the price to get the entire place sided. We also hated our old windows... 26 years old, and they were wooden. One of the previous owners (or hell, maybe all of them) painted over them, so they were completely sealed shut. So we just bit the bullet and got the entire thing done. The windows took 1 very long day to complete. They got to my house around 11am, and didn't leave until 10:30pm. I was amazed that the crew stayed that long, but we're happy with the results.
So... yeah, it was visually important for us to change, plus the storm blew off a large section in the rear of the house, so we only had to cover about 2/3rds of it out of pocket. It became worth it from that point alone to do the entire thing and not just cheap it out and get the same color that we already resented.