After leveling several dps and trying my best to get their respective ins and outs and seeing what distinguishes a bad dps from a good dps, I have a newfound appreciation for at least decent dps and comm them quite often. No matter which role I currently play.
A decent and espcecially a good dps can make a run insanely fast and smooth. Good dps melts even huge pulls and considerably lessens the strain on the healer. And skipping mechanics on boss fights is also nice like ignoring the last set of seeds in Grand Cosmos or skipping the last Seabed Ceremonry in Andyr.
If they also use any support they have, brownie points!

If I see a dps do his aoe roation and single target rotation properly, use his ogcds on cd (I see way too many dps not using their party buffs during big pulls...) and play mechanics, that's almost a guaranteed comm. I also appreciate funny or friendly people but there's generally not much talk in expert/ 80 roulette.