The first route is certainly one that seems faster. It also allows you to freely use ideas and actually start writing. The issue is that without guidance, the story and pacing becomes chaotic. Also, if you can't think of anything, then you have a Writer's Block which means you won't write at all either. It might be good for exercises, but not the ideal for writing a novel.
When writing a novel, the book needs some sort of flow. This means that not only does it have great scenes, it needs to build up to the scenes naturally. While it seems counter intuitive to think that planning something is more natural than free writing, there is truth to it.
In order to get the full benefit of free writing to be natural, you need to have complete understanding of the characters. When you write multiple novels with the same characters, this can happen quite well. However, when starting with new characters, like I'm doing, that's not possible. Unless you have the backgrounds and their characteristics established, you will end up backtracking and rewriting far longer than is good. If you backtrack a lot, then you can lose sight of what is still present in your novel. resulting in confusing your reader.
When I started the new novel, I had a lot of things planned, but not enough as I have come to realize. The main characters I had a good idea for, but I neglected the secondary characters. The result is they were essentially nothing but names. While it is important to develop your main character, fleshing out the secondary characters is important as well. They need to have a history, philosophy, relationships, and goals.
The result is simple. For a good story, you need to do a lot of planning, especially if you don't want to rewrite it multiple times. For me, finding the time to write it once will be difficult enough. However, once all the elements are gathered, it should hopefully be as natural as free flow.
J. D. Nyle