That Remington Ultimate defense Managed Recoil load with 17 pellets has a velocity of 1140 FPS. The 20 pellet load above is at 1200 FPS.
So my guestimation is that the 17 pellet load, going 60 feet slower, is going to be a low recoil load. In fact, its confirmed on the box, as they call it a managed recoil load, which is Remington speak for low recoil load.
Yes recoil matters. I once thought I was going to use a 16 pellet, #1 load, 12 gauge for home defense. Until I shot it, and found that it easily had 60-75% more recoil than some of the light recoil loads on the market.
Buy a couple boxes of everything, give them all a try, pattern them, and then decide if you like the low recoil load or prefer the full power load. I doubt 17 pellets, vs 20 pellets, is going to make a hill of beans difference to a bad guy.