I finally figured out how I was getting water all over the floor, even with the triangular diverter glued to the edge of the tub. I take "navy showers" where I turn the water off after wetting down and then turn it back on after I lather up to rinse off. Well, I now have a clear shower curtain and could see when I turn the water "off" at the shower head and it still dribbles a little bit. The water was running down the hose along the wall and running onto the edge of the tub. It didn't take long for enough water to back up and get around the traingular dam and onto the floor. Solution? Turn the water off completely.
So it wasn't only the faucet neck being too short. My new faucet worked well. And I didn't really have the problem until, I turned the water "off" at the shower mainly because I hand hold the shower head to get wet – it's just not quite tall enough for me to get my hair wet. Also the shower head doesn't always sit square in the holder but twists so the shower head is against the wall.
I'm slowly learning what's happening and will figure out solutions – besides the obvious towel on the floor next to the tub.