Bert, yes, they fit, using one of the adapter rings that come with the props. I had a couple of acorn nuts lying around that were right hand thread, and popped 2 of the left handed nuts off of a couple of 3DR props that were nicked, ground off the 2 little tabs, and they work. Noticed a bit more grunt on throttle. I have the timer on my radio set to 12 minutes. With stock balanced props and a fully charged 5100mah battery, after 12 minutes, my lipo checker shows 27% left. With the 10/4.7's it showed 37% left after 12 minutes. The slow flyers have a pretty aggressive pitch. I also have some 10/4.5's slow flyer's, and some 10/4.7 4.5's Multirotor props to try also. Another tid-bit, I had to change out one of my motors last night, bad bottom bearing. Also had a small piece of I guess balancing material (blue) that was sticking up between a couple of the magnets, and rubbing on the windings. I say must be for balance, as there was just a little gob, only in one spot. NOT blue loctite. I suppose I could send the motor back to 3DR, but I bought both my Iris+'s off Amazon, so I won't bother. I already had 2 new motors on the shelf, I bought from 3DR. I did not open up the Iris+ to change the motor, just cut the wires on the arm, soldered the new ones, and heat shrink tubing.
Here you can hear the bad bearing on shut down, and start up: