"right now, moving forward" is pretty bad phrasing honestly. Not sure what you want to know but I'd rather have Ovechkin right now this year
Depends on time frame. At some point Ovechkin is going to decline harder assuming they follow something of a common career arch.
Anything under 2 years is Ovechkin for sure for me.
Anything over 8 years is Hall for sure for me.
The way i took the poll is - your team can trade for 1 player today today (with or without cap, unclear). Who do you take. So it involves the right now, this year, but also keeping the player as a part of your team, until he retires/traded/FA, etc.
How long each player lasts depends on how long you think they last. They'll both last more than 2 years, and 8 years is a long time so debatable.
I personally still take Ovi without thinking twice. Simply a higher tier player, and he's on pace for ~55 goals and close to 90 points. He seems far from done. Plus - he's more entertaining.