Hi Tony,
Those store bought buffers are not going to be very effective in removing swirls from your car. They are OK to use to apply cleaner wax but that's about it. I used one for many years in detailing but when I started using a PC, the old buffer went to the boneyard.
The PC is ideal for novices who want to take their detailing to the next level. Some advanced detailers like Bryan and Todd have developed processes to get the best results from the worst paint conditions.
The big advantage of the PC over an orbital buffer is its peformance and flexibility. With the buffer you are limited to using cheap bonnets as pads, you have no speed control (either on or off) and they do not have enough torque to remove major defects. With a PC you have a huge variety of pads which can be used with almost any polish, you have a speed control and it has plenty of torque. It's a huge step up from a buffer and worth the investment.