Unfortunately most % are inflated by padding.
Also 2 people could play exactly the same but 1 guild kills boss 1 minute faster and thus the guy from that guild gets higher % too because (one of many reasons) bloodlust percentage-wise was a bigger part of the fight.
Ele ST is crap atm, there's no denying it either way.
You say you did 200-220k with 852 and he did 270k with 881. 881 ele would do probably ~300k tops with good legendary, maybe a little more. With same geared Frost DK and without dps legendary I get ~380k+ ST and would easily push past 400 with Toravon's bindings. My Ele sham which is 9ilvl below my main is nowhere near. Over a month ago (don't play my DK much atm) did 400k on Elerethe (HC) without padding numbers on trash.
But anyways, Ele is looking good on PTR
On shammy with 850 ilvl some time ago I see I did 93% and did only 232k dps on cenarius h (probably because there aren't enough parses due to ele being so crappy XD)
EDIT: 867 ilvl I see I did 300k on Nythendra, better than that 881 sham or w/e but still nowhere near my 880 dk even when accounted for ilvl difference.