I think it is a great trade for you...Kopitar is what he is : 70pts on a very low scoring team.
Johnson plays for one of the highest scoring teams in the league by far and plays on a great line.
Hubs is an up an comer and could easily net 50-60 this year.
2 young up and comers in a dynasty vs and set floor/ceiling vet........I like the potential by a long shot