What’s your travel style: serendipity or advance planning?

I’ve done both extremes and also in between. When H and I were dating and young we would go places without reservations or itineraries. One of my first memories of a trip to Europe with H was arriving in San Sebastián Spain on the eve of the running with bulls in Pamplona. Of course not a bed to be found and we ended up sleeping in the train station. This method worked well till we had kids. I remember one trip driving back from Sun Valley and we decided to just drive till we were tired. Not a room to be found for miles once we were ready to stop in Carson City… I remember being in a diner in Lee Vining at a pay phone calling every motel in Mammoth Lakes. I finally found a newer place with one room. After that trip I decided I don’t need to know what we are doing each day but I do need to know where we are sleeping.
I also used to pride myself on not taking organized tours. In the last five years I’ve learned that we miss a lot if we don’t sometimes take a tour. I’m talking day tours not a 10 days on a bus tour.
H and I also do charter sailing trips. I used to plan our itinerary but the last few trips I’ve done my research but go in with the mindset that the local chart briefer knows the area best.
I think with the internet it is easy to do research. I still check tourbooks out of the library but I rarely buy them anymore. With an iPad and smartphone it’s easy to do research and such on the go and much lighter. I remember traveling with multiple heavy guidebooks and sometimes ripping out sections as we went along.
Where I’m spontaneous in what we do each day I’m not one to find a last minute deal and go. I have a friend whose H searches out deals and they will decide to go on a trip with just a few days notice.
My sister and her family will also go camping with no reservations. I need to know I have a campsite.