Well I just joined this forum and this is actually my first post. But since nobody else has answered you, I figured I may be able to help you out.
I have at least one, and I’ve given them out to friends who were interested in starting fly fishing. The build quality is about what you’d expect for a 40 dollar rod, but I honestly think they cast really nicely. That said, these rods are not meant for big fish, big flies, or casting long distances. They are DEFINITELY not suitable for most any saltwater fishing. I’ve fished with mine on the small trout streams in the Appalachians, and it’s really well suited for that sort of fishing.
I’m sure it would be great for panfish and maybe small bass as well. Like anything else, it just depends on where you plan to fish with it. But it’s a perfectly usable rod. For the price, it may be worth having one, even if you eventually upgrade. It’s really nice having a second rod along when you slam your expensive new rod in the car door (speaking from experience).