Not sure why so many complaints. These are good changes.
For those chiming in about which way is the fastest....speed is not the only consideration in the process. Protecting the product is also important and if somebody is in C+ and expects overhead space....they are HIGHLY annoyed when a bunch of SkyPriority people sitting in row 35 get on board first and throw their crap into the C+ bin.
It's also annoying when SkyPriority people imagine they are the first boarding group. SP is quite a bloated segment these days with uninformed travelers who overestimate the value of their Delta credit card. These changes make it (even) clear(er) that SP is not first. I like that.
TBH, this C+ before the rest of SkyPriority is really the ONLY tangible change. The colors and branding are cosmetic without real impact / the same as what happens now. And the other change - PS boards after D1 - is an edge case and barely matters.