While you can choose between either of them, I prefer that floating foam bobber.
Here is the spring bobber in action:
Here is the “foam bobber” in action:
I really can’t say enough about these ice buster bobbers. I’ve used them for almost 20 years (since 2000) and I’ve never been disappointed. You can certainly use your panfish floats/bobbers that you use during soft water, but these things rock. I really like the idea that you can clip them down to the buoyancy you desire. They can get to the point that they are almost weightless when you have the right bait presentation.