I like to build from scratch, but I prefer maintain something on top of something. Less code to maintain since I can delegate part of my code to the technology built on top of it.

In that matters, for my professional work have a healthy long term life, I usually select on-top development style, and sometimes, if I have really good reasons to do, from scratch is the option. Of course, for learning and personal projects, from scratch is always a very fun choice!