Bodysolid's well made, with slightly better machining & finish than Powertec, but they're both good, durable & feel like gym equipment. Bodysolid also has a longer warranty (lifetime) and better parts support.
The advantage with Powertec is that they make different configurations including smaller single exercise stations like squat/leg press and lat machines. Powertec often doesn't have replacements readily available; with them it's better to order parts that can wear before the need arises. Parts support isn't too big an issue because the machines are durable and replacment parts are inexpensive after the machine's out of warranty.
Worth the difference over lower-end brands like Yukon or NY Barbell-the pulleys will be smoother, better quality, the finish better. More money but worth it over a long life plus there's the warranty.