among three voting choices, chances for spurious trip is highest if 1oo2 voting philosophy implemented. i used to handle a steam turbine that has issue on one of its radial probes. 1oo2 arrangement. in that particular year, we had 3 unnecessary PLANT trips initiated by same radial probe. after a discussion, the team finally decided to remove the trip considering the train has been running good for years. it was not there in the first place (1980) but due to recurring issues on coupling failure after few years running time, the radial trip was implemented. the issue on the coupling resolved and since then there were no radial vibration issue but the radial trip interlock was still there until the issue on the probe emerged..
yea, i like 2oo4 too. the place where i work now has 2oo2..