The floor press will build massive triceps and lockout strength. The purpose of the floor press is to work the top-range of your pressing. Since you aren’t able to use any leg-drive, as you would in a traditional bench press, most people can’t handle the same loading. This will actually allow you to recover faster between workouts.
The floor press can provide insight into whether or not your bench press technique needs work. It says a lot if your floor press numbers are close to your bench press numbers. It indicates that you’re not effectively using your legs in your bench press.
You can do floor presses with a barbell, dumbbells, or specialty bars like a football bar. Typically, the floor press will be done with max effort work, building to a 1-5 rep max, but that’s not to say you couldn’t use this with higher-rep ranges.