I have enormous mitts and loved one-handed use on my 4.7" 7. Ultimately screen size won out, and I sacrificed reaching the upper left corner with my thumb using the one-handed pinky cradle approach. Fast forward to the X. While it is barely larger than the 4.7" models, it is nearly all screen. Meaning, if you pinky cradle it, your reach will be near what it is on your plus (except the X will be a bit less wide). That upper bezel that you didn't 'need' to reach before on the 4.7" will now be screen. In other words it'll line up with the height of the Plus screen. I'll be curious what this means for one handed use and trying to reach above the upper left app to pull down the Notification Center. Particularly with the removal of reachability.