Best O series Swagelok valves:
Have an orifice size of 0.08in, compared to 0.03in for the 52-1-12
Cv is 0.09 for swagelok, and 0.01 for the 52-1-12
Full open 8 turns for Swagelok compared to 24 for Ideal to achieve full Cv
You'll never find a more indeal valve, than the ideal 52-1-12