When chronying my Indy .22 I shot 100s of shots over two chronys, ProChrono and Red chrony.
As far as accuracy goes, they gave the same readings (obviously, the one that was closer was reading a few f'ps hotter). Obviously, w/o knowing the actual true fps, its impossible to tell which one was closer to reality. So, I call it a draw.
As far as precision, RED was almost always showing about 20-30% more of extreme spread compared to ProChrono, (Even though RED pretends to be more precise by showing speeds with 1/10s of foot per second) - so I must give it to ProChrono.
ProChrono also had less 'no readings' - another point to ProChrono.
Red is more compact for storage, nut takes a bit more to set up.
Tests done indoors, incandescent lights shining from the ceiling down.