Up until last year, I had gone through life with no stabilised (IS) lenses... until I got the 24-105L IS last year cause I was forever @75mm on my old Tammy 28-75 and rarely @f2.8. Roll to last week and I snag a great price from the refurb sale on a 70-200L IS - the f4 version - so think ya know... I can swing it right now.
Holy Crap Batman.... I absolutely love my faithful 70-200f4 nonIS and never dreamed of selling it.... Did I say Holy Crap yet..... but I think it's going to get some portraits done when I get time cause this IS version is well Holy Crap!
Stay away from IS/VR.... I't not great on your wallet :-)