I've been doing a lot of training hikes on the weekend, most of it on rugged terrain, and have been experimenting with how boots vs trail runners feel. I've been going back & forth a lot, and finally decided on shoes. Here's my take:
Boots, pro: Insanely better on wet trails with lots of rocks, roots, and steep sections. I have a lot more stability, and can handle tricky sections with confidence. They should last longer than shoes.
Boots, con: They're heavier (even though mine are light weight). At the end of the day I want them off. I felt like my natural walking pace was much slower in boots. And even though they fit properly, mentally I feel like my feet are boxed in.
Shoes, pro: They're much lighter. They're more versatile. They're better for urban areas and non-technical trails (though we don't have many of those here). My walking pace is a bit faster.
Shoes, con: Less stability. I rarely grab a walking stick when I have boots on, but with shoes I absolutely want one in steep sections or in muddy and slippery areas. Possibly less rugged - I know my boots will last a whole camino. I'm not convinced my shoes will.
In the end, what swayed me was this: If I bring my boots, I will be wearing those boots every single day. If I bring shoes, I can switch out for sandals once in awhile & tie my shoes onto my pack.