Historically on a bright day like yesterday when I put it in Shutter priority, it will adjust my aperture which annoys me because I want the shallow depth of field. So yesterday I shot in manual as I said... and I'm sure I overexposed some of the shots. It's really the 2nd day that I REALLY went and shot with the lens, so I expect better results. I'm thinking of shooting in aperture priority and setting the iso and then allowing the shutterspeed to vary (on a bright day). In doors... that will be a tougher nut to crack.
This is exactly why Nikon cameras have proper Auto ISO capabilities.
Even on cheap Nikon bodies you can do this:
1. Set the camera to Av and f/4.0 (or whatever you want)
2. Set a minimum shutter speed to catch the action that you want (like 1/1600). On mos. cameras you can also set this as a multiplier of your focal length.
3. Leave it on Auto ISO
This lets you do exactly what you want: have the DoF you want while keeping the shutter speed you need. If a football player runs into the light and the camera pegs out at ISO 100 it can increase the shutter speed above your minimum. If a player runs into the shade the ISO will automatically be increased to keep the shutter speed above your minimum.
It works very well in my limited experience.