I have had experience of 2 10x42 sidewinders, they both suffered the same fault. When the windage was not dead centre the cross hair appeared to be off centre and the peripheral image around the edge of the sight window was not equal, blurred at one side and sharp at the other. This made it impossible for the scope to tell you when your eye was central to eliminate px error.
The best thing for these scopes is to mount them on a Chinese springer until the gun or the scope breaks then drop the scope with the rifle still attached straight in the bin!
They would be useable for their intended purpose as when px'd for each shot error shouldn't be a problem but shooting many yards away from the px setting and you didn't know where to put your eye?
Hawke do make some scopes that work very well for HFT, from the 2 examples of the sidewinder I have seen my opinion is this is not one of them.
Maybe I have been spoilt with using a NF for the last 5 years? I have still to find a scope at any price I would choose over my NXS 2.5-10x24.
If you use blurr in HFT then I would consider the scopes primary purpose is to feed you information about the range, some scopes are better than others at this which is what makes a good HFT scope. next is suffereing very little px error (small objective helps) and the scope being able to let you know when your eye is central to minimise any error. Most scopes have a useable reticle so is of less importance.
Exceptional glass and the reticle design become more important if you brackets plates or kills as your primary ranging method which is where the little Mk4 seems to excel.