I'm kind of on the fence about it. On one hand, The idea of fighting alongside these monsters is still kind of weird to me, and that weird mega stone-ish thing doesn't really look like it belongs in Monster Hunter. On the other hand, you can ride a Diablos!
Also, thank God that felyne with the massive head isn't what all felynes look like in Stories. I was genuinely worried that they ruined the felynes.