Since Pigeon Forge in August is sweltering hot, our family decided to Putt Putt indoors. For the price, we found the indoor course rather underwhelming. It is not visually interesting and can get crowded quickly if playing at peak hours. The unique aspect to this course is you spin a wheel (optional) prior to putting each hole and add an extra element of "fun" to the putt. It was hit or miss with the kids (one of our children disliked spinning the wheel).
It is the only course we played during our time in Pigeon Forge, so I cannot compare it to others. However, we left with no desire to ever return for either the indoor or outdoor course.