One of my favorite bikes from when I was a kid was a Huffy BMX bike. It was my first BMX style bike and I rode that thing all the time for years until it was finally beyond repair. I will always have a soft spot for Huffy bikes.
If it fits you well, goes forward when you pedal, and stops when you apply the brakes I say keep riding it. That said, if you're curious you can always head to a bike shop and test out a few to compare with your current bike. You'll figure out quickly if your bike is good enough or if you're really missing out on something else.