I have a TRX and love it. I take it everywhere I go, even with me to the gym. There are things that you can do with a TRX that you can't do with anything else. Except maybe the knock offs that you have mentioned.
I went through a TRX class with one of their reps and learned all kinds of stuff. I used to geek out in the studio and come up with fun new stuff.
I've got some crazy core exercises that will crush anyone. But, my favorite is to hang them from the squat rack, plant your feet against the rack and lay back into a true horizontal body row. They're also great for taking simple movements like bicep and tripcep exercises and adding core work to them.
180$ is expensive, but I trust them. Pretty sure they're not going to let me down.