From day one on my 650 I used the IF roller handle. Top quality works great little to no effort to use. Then I had a chance to try the Dillon aluminum roller. I liked it better because I felt it gave me a more tactile feel when seating the primer. The IF was too smooth, just too easy. I still use the Dillon and sold the IF roller to a friend for use on his 550.
I dont believe they sell the Dillon plastic handled roller anymore but if they do I would not buy it. I had one on my 550 and because the handle is triangular in shape I always felt for a flat as I used it, annoying to say the least.