I haven't gotten much chance to play S:LW (only played the demo at Sonic Boom), so I'm not really qualified to speak to the entirety of the game, but what I played I didn't particularly care for (other than the 60fps). I like the Colors/Generations formula, and I didn't think they needed to change it that much. The new run button system just doesn't mesh with Sonic IMO. That being said, reviews seemed pretty polarized on the game, so clearly a fair number of people liked it, even if more people didn't.
I don't really see much wrong with how SEGA is handling the story-telling; I think in the long run it's better for them to have light-hearted plots that appeal to a younger demographic, than try to pander only to us old timers who are nostalgic for stuff like SatAM or Sonic Adventure. This isn't to say that there shouldn't be any serious tone in Sonic at all; if the writers think of something a little more serious that they think is going to work, then by all means, they should give it a shot. But trying to force Sonic into a super serious role like we saw in 06 or Shadow isn't a good idea.
Ultimately, what will keep Sonic selling is good gameplay. Make Sonic control well, and give us those classic slopes, loop-de-loops, and branching paths. Maybe something like the parkour system can be a good long-term addition to the franchise, if they can refine it over time.
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