Not on a single pally, but I've tried shockadin builds on my 5x pally group. It's...underwhelming. Tried it in Halls of Lightning the other day. One pack of earthen would eat almost all my mana (not counting Divine Plea). My caster gear on them is about 50/50 INT+CRIT or MP5 gear. I think last time I looked they were somewhere around +1200sp. Not great but I was doing much better with 1300ish sp on my druids without the mana problems and with a LOT more DPS. The shockadin builds I've tried put out about 800dps. Losing crusader strike and divine storm is painful. :P

That's my perspective from pure PVE. Might be worth a look in PVP as the 40 yard range on judgement and 20yd range on shock sound nifty. I've run dailies with them in shockadin setup and they went just about as fast as normal dailies go. Anything with less than 25k health still dies in about 2-3 GCDs. I'd batted the idea around myself but they're so much more squishy than ret pallies that I just haven't done much with it. :P