I assume in 3-5 years you'll be wanting N+1. If that's true, go ahead and buy the 520 now; it's probably best for your projected commuting usage, and the 520 changes very slowly, so in that 3-5 years you'll be as happy as you will be tomorrow with the 520. The gravel bike is changing much more rapidly. In 3-5 years if you get the 1120, you'll think it's as modern as Hamurabi's code inscribed on clay tablets. So you'll be ready to roll the 1120 into a deep lake and buy a new bike then, which you may want to do to supplement your 520 commuter anyway.