I love both small & big battlestar. Nothing like them and kicks in up some.
For the areas you mention:
I like the little battlestar for the calves, hamstrings, &heel cords.
It gets in and cleans up the small stuff that was left behind by other tools.
The big battlestar is great on the quad high ham, calf, adductors.
The more detailed areas the small battlestar is more effective.
Both are definitely well worth the investment.