Still Eichel for me. Statistically they have been remarkably similar this year offensively. Tage has a slight PPG lead but a slightly heavier PP usage and shooting %. Their ice time is almost identical - good but not massive ES time and PP time (suggesting both have upward mobility left in their actual output), secondary PK time, right down to the poor face off %. Both also lead their teams in scoring by a considerable margin.
I certainly buy there is even more left in Tage's locker but I also think it's a mistake to say this is the "fully back/reborn" Eichel at this point as well. He's been uber efficient this year and has in the past been able to maintain star level performances at a much higher usage. Vegas has a deep line-up and Eichel is certainly not getting Drai/Mack/Matthews type minutes.
The biggest thing for me is that I feel Eichel has been the engine of a once-again powerhouse Vegas team. Certainly, a healthy Stone has helped as well...and other factors like Stephenson continuing to improve and Thompson being a revelation. But Eichel's has given the Knights a superstar focal point for the offense - something they have sorely lacked.