Tried two, albeit inside a very long shop with limited outdoor vision.
The optics were quite average, although not far behind the budget Zeiss Duralyt range or whatever they are called. Build quality was fairly basic, the tactical style one was a bit better; I heard they had to skimp on build a little to make up for the optics cost, but don't hold me to that.
Nothing wrong with them. On the plus side they are extremely compact for the magnification, and I thought quite light. The optics are probably pretty good, given the length to magnification ratio, that is probably why you get such good optical quality from yours at 16X.
I bet the 4200 at such magnifications is better; they are a very long scope, right?
It would be interesting to compare. FWIW, bought a Leupold 45X Comp instead eventually, very nice, couldn't afford to keep it sadly.