Well pve gear didn't last long more than 10 seconds, and his pvp gear took me awhile to drain his mana, but I ended with a lucky string of crits/procs and 44k burst.
Then we decided to duel with him actually fighting back/dispelling FlS etc. I don't have any pvp gear, and I wasn't really taking him seriously. I started opening up on him building some charges for Fulmination and that's when he started attacking. Didn't realize it but I was at ~40% health and then stopped to heal. Never got the heals off and died. Was kind of shocked, but thought it was because I hadn't been paying attention.
We reduel and he ends up running me oom as elemental. All he did was spam exorcism and holy shock on me with the occasional stun to try to finish me. Eventually he ran me oom and I couldn't keep up. He didn't even use a 10th of his mana doing that. Literally refreshing water shield was hard to do without dying and trying to get in wind shears/grounding totems.
So then we just screw around as me in my resto pve gear and him in pvp gear. I figured it would go no where, and it while he could do some damage not much would happen. I'm doing some pro LB spam with LvB every now and then basically doing nothing. He finally started trying with stuns, and avenging wrath. If I had ES up he would drop me to 20% health or so. With riptide and/or earthliving I would hang around 25-30%. Sometimes less sometimes more depending on crits etc. He never killed me but his burst was insane as a holy pally.
So I started looking over talents of holy paladins:
20% more holy shock/exorcism damage through talents
denounce makes exorcism cost like 200 mana and gives a holy shock 50/50 chance of making the next exorcism free and instant
conviction gives a stacking buff for damage and healing
Add that in with exorcism being like a 1.5 second (before haste/talents). He was hitting me for 4-5k non-crit.
Sure I don't have any PvP gear right now, so if I did have it the damage would of been less, but I'm sure I still would of lost in the end as elemental, and resto would of went no where (but I lock pvp) but seriously wtf? Holy paladin damage is off the charts. Even in pvp gear he would of been able to do some serious damage and no healing spec should be able to do what a holy paladin can do right now.
I can just imagine at 85 with a holy pally partner. They won't just help apply a little damage to a stunned low health opponent they will be closer to a nuke.