REX Weather fore is more accurate to METAR data. But it has some major flaws for me.
Its XML output for apps like Pilot2ATC seems to be an hour off on some airports.
Transitions are not smooth.
The weather is not as dynamic as in game weather.
My solution is I get ATIS from in sim so i know the pressure and winds are going to be correct to what is actuially happening, even it it does not match exact to IRL weather that Pilot2ATC gets. If there is a conflict from in sim ATIS and Pilot2ATC controllers I default to in sim ATIS.
Two things I am hoping happen eventually from the last dev talk. One, an API for in sim weather is created so PIlot2ATC can get its weather from the sim. Two, METAR data is going to be ingested earlier in the process on the back end weather engine.