I bought one of these as part of my ongoing series of tests of cheap SM58-style microphones, comparing their performance against a real Shure SM58.
Yes, the mic is very cheap, but it feels and sounds it. The mic feels light and insubstantial, with a coupe of plastic, rather than alloy, parts on the grille. Note that the grille isn't compatible with an SM58 grille (if it ever needs replacing). But the mic is wired for balanced operation (unlike quite a few low-cost SM58-alikes I've tested).
Handling noise is very noticeable indeed and relatively high pitched, so isn't reduced at all by a mixer's high-pass filter.
Output is slightly down by just under 1dB compared to an SM58. feedback resistance is similar.
The sound is both muddy at the low-end and overly bright at the high-end, with a lot of very noticeable sibilance. It really doesn't sound nice at all, and there's only so much you can do to remedy it with EQ. The frequency response I measured is relatively similar to an SM58's, but somehow the small differences on paper add up to a much bigger difference in reality.
The paint on the body isn't tough, and simply fitting it in its plastic clip a couple of times left the paintwork scratched, so it's quickly going to look quite tatty.
So for a stage vocal mic, I really wouldn't bother with the SL84C at all, but pay a few £/€/$ more and get the older Behringer XM8500. That's not a perfect mic, but at least with that mic you can turn down the bass and increase the treble and get a sound that's very similar to an SM58, with reasonable handling noise and a strong output signal.