Actually, every time you open Acrobat it's had a new security issue. At least, it's that way for me (though Windows is not my primary OS, so I don't open Acrobat that often).
Even if Windows is your primary OS, there's no reason for the typical user to have to run Adobe Reader on a regular basis. Just use a nice lightweight viewer like PDF-XChange, Sumatra, or Foxit instead.
Windows is my primary OS, and I don't even have Adobe Reader installed.
I've found Sumatra to render extremely slowly when zoomed in past 100%, particularly on PDFs with high-res images and/or vector images. Are the other non-Adobe readers better at this?