Amen, fellow former brother of the light.My first character was a paladin, really enjoyed (didn't know any difference at the time), but raid healing (and buffing) was soul destroying.
And I was playing a paladin back in the days of 40 man raids, with 5 minute single target buffs. Before buff mods. God it was awful. But then playing a Retadin back then was awesome. I was the second person on my server to get a legendary, and the PvP Paladin back then with reckoning was good. With Sulfuras it was godly. Could easily one shot people with reckoning bombs.
Of the two, I'd definitely pick priest. Although I've sadly been forced to spec Discipline in order to play Arena's, I still enjoy my Priest. Longing for the day Blizzard fix Shadow!