I've had a couple of strawberry sodas recently, and it's become one of my favorites. But this really surprised me:
Got it on a complete whim, based on childhood memories of often ordering it at restaurants. It was glorious. Very fruity (mostly cherry) with just a hint of something else that I couldn't identify, but it was just perfect for taking the edge off the sweetness and left no aftertaste.
Shirley Temples are made with grenadine, which is a syrup made from pomegranates. Maybe that's what you're tasting.
I love strawberry sodas. I've got to find some Eli's strawberry. All I ever see around here is the blueberry or the root beer.