I decided against the sport package mainly for this reason - having all 4 wheels identical allows full tire rotation. I've rotated the OEM Potenzas about every 5000 miles, and the tread left on each one is almost equal, with about half remaining at around 20,000 miles of total usage.
The winter Dunlop M3s are directionals, so I've rotated those every 5000 front to back and vice versa (no criss cross, obviously). Once the left hand side tires are worn down a decent amount more than the right side (a lot of right-hand turns with on and off ramps in my area) I plan on having the tires flipped on the rims so I can switch sides with them and keep the rotating going.
Personal preference, I guess - I don't mind waiting as long as possible before having to shell out another $1000 for new tires.
Helps when you take the wheels off every now and then to check the brake pads and other stuff in there, too....make sure it's all good.
Aebous, if I were you, I'd have them rotated side-to-side as long as it's free anyway - why not? Will help keep the wear even....