Ok, just finished both Mania and Forces this weekend.
I gotta say, I'm kind of stuck between both your points Barry, TA.
Mania is perfectly crafted, but does feel dated. Forces would have impressed me, if Colors and Generations never existed.
They both feel like fan games to me.
I've grown to prefer the modern boost gameplay when it's done right, but I'm sure Mania will be better regarded though, so there is probably more of that coming.
No complaints either way. I love Sonic. I just love spending time in that world.
Looking back, I'm starting to feel that Sonic Colors was the last great, wholly original Sonic game.