The rear weight stabilizes the frog and makes it easier to move it from left to right. The welded eyelet limits water ingress; the drainage system expels water that accumulates during the cast.
Let it drift through the grassy patches, then pause in a clearing. With short tugs and a little slack in the line, you can linger over a hot spot without reeling in too quickly. Wait until you feel a bite before pulling the line taut.