I do use the RN Notes more than I thought I would, but not a ton. It is just basic stuff, but sometimes as a student I need to be reminded of the basics (assessments, etc) when I'm nervous or if it has been awhile since I performed a skill.
I use the Tabers and Davis constantly but I also use the RN Notes and the Nurses Manual of Lab and Dignostics that comes with the whole package.
Just my 2 cents