The only mistake you made is buying a PG57 instead of an SM57. Your mic is a copy (by the same company) of the most popular mic in the world. (not *best*, most *popular*)
Why do people use SM57? It's hard to break, works with a wide variety of PA's and preamps, and usually doesn't totally suck on anything. It is a standard low budget band vocal and instrument mic. The SM58 is almost exactly the same mic with an internal wind screen. Put a thin foam windscreen over your PG57 and you'll get a very similar sound. The other reason folks love the 57- It never goes away. On middle level soundstages (community TV stations. etc., it gets a lot of use on sax, horns, and percussion, as well as guitar cabs and even piano.
At the high-end, big bucks recording studio, it often sees duty, but now it's mostly narrowed down to snare and guitar cabs, depending on the preference of the engineer and producer. Go find me a big name studio that doesn't own a pair, at least, of SM57's.
What's not to love? Sometimes a cheap mic is the right mic, and over the years, the SM57 has been right a surprising percentage of the time. Will the mic you have work for you? Who the hell knows? Plug it in, and see if you like what you hear. One warning with cheap knock-off mics, which goes for most other gear as well. Quality control is not as good as on the higher end models. This means they vary a lot. It's up to you to get your hands on a good one. The best PG's are probably about as good as an average SM. Good luck.-Richie