So it sounds like he's more of a shoot first type of player. Exactly what we need for the third line. I think he'll mesh well with Johansson, that is if we get him signed obviously.
Eller isn't so much a shoot first player, but has historically played with absolute awful goal scorers on his wing so he gets the bulk of his lines goals.
Eller isn't a standout shooter or passer (which gets him flack amoungst the dumber elements of Montreal's fanbase that think a forward only helps offensive in the offensive zone). His main attribute is that he's a top notch puck carrier and a pretty strong puck retriver. So he isn't as good at directly scoring as he is putting talent linemates in a position to score. Even as a winger last season (a position he's much less effective at than center) he did a lot to help Galchenyuk score, which showed up on their very high on-ice goal rates together, but didn't translate into Eller getting points himself.
Eller is very well suited to be the 3rd C in a three line offense system. Either he's picking up the tough defensive assignments to help the top two line score, or he can do a lot put offensively talented but flawed depth wingers in a position to provide secondary scoring.
The upshot is that he's very good at improving puck possession and tilting the ice in his team's favour, but relies on teammates to translate that into more goals scored.
Also a very strong pker, his power play skill at this point is unknown (coaching staff's deep attachment to Desharnais medicore skills with the man advantage permantly blocked Eller from getting any kind of a shot with the man advantage), his skill set suggests he might be very good at power play zone entries and can fill a role in front of the net, but he's never been given enough of a chance to know for sure.