Eller ranked 102 in points for a center last year.
He ranked 61st in ES TOI for centers.
He ranked 98th in PP TOI for centers.
He ranked 66th in SH TOI for centers.
Keep in mind the NHL.com list includes wingers at center so this number is actually higher. He's already played as a 2B center.
He had more ES TOI than Carter, Richards, Toffoli who are all listed as center but play more than one position...
This is one team even, they are all better.
Stoll played less minutes, produced more and is more versatile. Once again, same team.
I think Eller is overhyped due to his size and the market he's in. He's an very good top 9 guy but he's not a top 6 forward. You can easily name a bunch of players you'd rather center the 2nd line than him, over 60. I won't bother but it's not that hard, it's Eller, not a superstar.
The same can be said about DD and at a lesser scale, likely 30 centers you'd rather have on 1st line than Plekanec. All of which are valid as the habs lack an established elite C.
All this being said. What you quoted said he will never beat out Plekanec and Galchenyuk for top 6. I can bring up LA, Pittsburgh, Chicago, etc... but even in Montreal, he's not better than those 2. He'll forever be a 3rd line C, even on a team lacking a real #1.