Yeah, I got a lvl 7 Blitzwing and a lvl 6 Ruckus almost a month ago. Cashed in everything I had to level up Blitzwing and its taken 4 weeks to get Ruckus up bit by bit:
Typically I decided since it took me so long to get Ruckus up that I would then finally call it quits. A full had of level 6 cards with a level 7 leader. And then today I get a lvl 6 Dirge & alt mode from turning in a bunch of episode medals
Sad thing is he's probably more powerful than Ruckus. If I do decide to keep playing might just save my stores for if I get more level 7's