I don't really know that I miss anything. The things I might've thought I'd miss are the things that ended up souring the taste of Rails.

Having to come up with my own abstractions or recreate familiar conventions or set up a database were areas where I had to cut my teeth, but I also had to cut my teeth on Rails when I was learning it.

Rather than missing anything from Rails, I find myself using Rails' conventions as a loose model and then simplifying it. For example, my "templates" are now just functions that render html. My "layouts" are just functions that get applied to templates. I don't need to read Rails' template rendering guide to come up with a hack. Instead, modifying my templating system is trivial and obvious.