The two are virtually the same, both could benefit from the rear camber arms, slight variations in manufacturing of your vehicle could translate to needing it more or less, not a deal breaker either way.
As for reasons to go one or the other, MPP pioneered the vertical spacer for the Model 3 and Y, the rest are pretty much copies of their work, you can see it with some other parts too (ex, there's another brand that makes
Camber Adjustable Front Upper Control Arms 'just like' MPP's, claims innovation but was released way after MPP's .. you can draw your own conclusions).
One sure reason to go MPP, for me, is their level of communication, they respond quickly, sometimes even if you aren't their costumer, which is commendable. Meanwhile their competition (esp with some of the coilovers) have been found to have just a bad product (making lots of sounds during operation) and pretty much just left people hanging - never got back to them, or did with unhelpful info, dragging their feet and claiming "within spec". You can search the forms and find out.
Speaking of ground clearance, the
Comfort Adjustable Coilovers for Tesla Model Y by MPP can be set to a ride height that is 1" higher than stock height, this is not the suspension's MAX height (it is advised not to be at the absolute max as that results in bad driving experience), a little on the pricy side but if you wanted a whole extra inch .. that's one thing you could do (in conjunction with the lift kit and the big tires)