Change I like
As a GS flyer that spends lots of money on United, I'm very pleased with this change.
Not only are the rewards now better for me, this will weed out the mileage inflation for lower tiers flyers, and allow me to use these miles for more redemption tickets and upgrades.
The airlines have known for years this had to be done. I'm happier that DL and UA are ripping off the band aid rather than dragging this out over multiple years.