Owen.
Vardy and Owen are fairly comparable when isolating their Premier League records, but beyond that Owen has a couple of extra layers to his portfolio that Vardy cannot match. As clinical a finisher as Owen was, he wasn't just about goals. While Vardy's threat is mostly confined to the shoulder of the last man, Owen presented more danger further away from goal. He could pick up the ball in the middle third and if you gave him any space you were in serious trouble. And his razor-sharp reactions and instincts in the penalty box ensured he buried the closer-range opportunities irrespective of stage. Club and international defences just couldn't live with him for the majority of that 1998-2003 period.
Generally yes, but not always. Up to 18/19 I think Owen would have been slightly higher rated. He burst into the English game and quickly became a heavy goalscorer, scoring 23 goals in his first season in the team at 17/18, whereas Rooney's first two campaigns only yielded single figures. Then they had those great tournaments, although again Owen would have been slightly ahead based on the wow factor he showed against Colombia and Argentina. But then at 19/20 Owen dropped off a couple of levels and looked quite one-dimensional for a few months - heavily one-footed, struggled against deeper defences, got his first hamstring injury and briefly lost some confidence in front of goal. At this point Rooney was now at United and was looking like hell of an all-round package. Then Owen bounced back, improved his left foot hugely, broadened his game, and I'd say he was more of a threat than Rooney up till the age of 23 or so when injuries finally overtook him.