I have played 12 stringers for many years, and started with an old Stella (Leadbelly ?) and currently play a Washburn which keeps tune and has an action lower than most of my six stringers.. I also have an Ovation twin neck which includes a 12 string set up. only problem is that arthritis and age are making it increasingly difficult to play barre chords. I agree with Richard about polishing and only use designated guitar polish. Goes for the banjos as well.
Happy New Year and keep plucking/strumming/flat picking etc.
Pete