Just watched yesterday's episode. I liked it. I feel like they're making DB earth mysterious again, with Popo straight telling Goku he's not up to speed anymore. With DBZ always getting closer to its end i was ok with progressively more cataclysmic enemies, but super's been great about doing awesome things with small scale threats. I really liked 17, and i can't wait for his reunion with the rest of the cast.
As for power scales, Frieza Gold is Canon, so we have to assume that someone's ability to match super saiyan blue has to be related to their natural power levels, an also greatly effects the speed and effort required to reach that height.
Frieza was a beast, but 17 was at least twice as powerful at his base so in the world of Super him being as powerful as Blue makes a lot of sense. Buu was at least as powerful or more so than perfect cell when he debuted so he's theoretically able to reach blue much faster than the previous two.
Krillin has to have tapped into pseudo god ki with his meditation business from his ark, that's where his jump came from and everyone else is going to get the same thing. Even if Gohan never goes blue by this point the groundwork has been laid for all characters to reach Goku levels if they're either strong enough in their natural untrained states or willing to do the leg work to tap God ki. Even Yamcha.
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