RE provide a poor PSO service IMO. I stopped booking them couple of years ago after a line of random cancellations at NOC, DUB, LTN & GWY. Weather diversions are understandable but I suspect the PSO is bottom of their priorates when issues arise elsewhere in their commercial network, there's no accountability or records published as far as I know and they get PSO subsidy either way (eh hello minister, this is taxpayers money).
Very frustrating missing business meetings or connecting flights while sitting at the gate on a beautiful clear morning and being told the aircraft was never sent "due to adverse weather, technical issues, late aircraft positioning".
On the numbers I haven't flown for a while and they aren't published but I'd imagine Irish Rails new early-bird Westport - Dublin service is a more reliable option for many pax.