Several people have confirmed the findings now.. however I haven't seen any maruaders/sentinels confirm it. I would assume you should switch to the elemental one but I would definately parse it for yourself considering the paucity of data here from knights/warriors.
I posted some askmrrobot sentinel parses that showed a low crit rate with the dread guard internal relic (http://swtor.askmrrobot.com/combatlo...ayer/5#d=0,b=1
) and a relatively high crit rate with the campaign elemental one (http://swtor.askmrrobot.com/combatlo...ayer/8#d=0,b=1
) but i'd confirm yourself since I dont know the stats on the players making those parses (though there are probably near/better than 1.4 bis)