I agree - mix it up everywhere you can. I LOVE the calf work in both PS:Legs and GS:Legs - both kill me every time. I am a huge fan of calf raises where you have extended range of motion - so you are up on some sort of step / block of wood / etc., so that you can really drop your heels down low on the downward motion. There are a few options on I believe PS:Legs shown, that you might want to mix in - one where Pat is seated with heavy weight across her legs just above the knees (she uses a loaded barbell, you could also just pile on a few weight plates if the barbell wasn't comfortable), and she does raises that way (again, I'd recommend having your toes elevated so that you can drop your heels). Another crew member is shown doing one-legged raises, while holding onto dumbbells.
Have fun mixing it up!