I currently play both formats. I do it because in Modern you run into groups of players with maxed summoners for the level(Silver/Gold). My mostly Bronze deck has a hard time playing against some of those accounts. When I hit 2 or 3 losses in one league I switch to the other league and see if it looks better.

I also have noticed that Wild is paying more than twice the amount per RP than Modern.

I am currently at Gold 3 in both leagues.
I question if they have implemented the pools per league. I didn't see any change when I advanced between leagues in payout per RP. If truly pooled it should have shifted due to different number of players in each league.
!PIZZA