Personal opinion alert!
The massaging seats are nice but not life-changing. If that was the only thing you got with the platinum upgrade, they're not nice enough all on their own to be worth it. To be honest, I'm not sure I'd even spring for them if they were a stand-alone $500 option. But taken together with the nicer seat leather, the other upgraded interior materials (real wood appliques, light colored headliner, darker interior plastic trim pieces, platinum badging, etc.), power boost, sound dampening, satin chrome exterior trim, yada yada yada, the platinum trim was completely worth it.
Same goes with the Max. It's not that much longer, so the maneuverability is not substantially different. But you get a LOT more usable space behind the third row plus you get much wider rear door openings. I also think the proportions of the vehicle as a whole look better with the max, but that is a 100% subjective view.