As much as a mag hoe I am, I would argue against this.
Like I stated The X-valve is phenominal at shooting extremely consistant, at high rates,
But when you fire off one at a time, or even spaced out. Each ball is subject to the heat inside the X-valve, when you shoot the X-valve heats up, expanding and allowing more air in, ( which is why the faster you shoot the higher the Velocity gets with a mag) and of course the faster you are shooting the more consistant the heat inside the Valve becomes (thus consistancy, same amount of air goes in each time)
So for single shots, the consistancy is always a little bouncy as depending on 1 BPS, or 2 BPS, or 3 BPS all the way up to 15BPS might mean the difference between a "+/- of 10" or "+/- 5" or at high rates, a "+/- 2"
Are the the best looking markers? Hell yes,
But to be honest the Q-bow only takes advantage of the Valve, its alot more logical to slap a Halo or a Prophacy /Rotor/Pinokio/ what-ever else on top.
I would argue the Super Nova's to be the best "sniping" marker as they operate at insanely low Pressures and the sound signature is actually nothing. maybe sir Piller will join in this discussion, write a entire wall of text of knowlege which we can all stare at for hours on end.