CO domestic F recline is 7", so 7.5" is decent... Every time, when I am flying in Y, I always feel like the seat reclines just short of the position that is necessary that you can sleep without your head rolling over. Another 2 inches surely will easily keep my head where it is while sleeping if I don't get a window seat, and I hate having to rely too much on the headrest...

Personally, I think UA/CO will look into revamping some Y seats to create a premium economy section, but reducing the # of E+ seats on international birds and limiting those seats to Plats or higher and for those who paid for it... However, the exit rows will still be available for lower tier elites and lower tier elites can move up into premium Y at OLCI if there are some seats left...

Basically not something like Virgin or AF, but offers additional features like:

Free spirits
More legroom
Extra recline
Priority boarding after elites
Dedicated F/A - just one
Dedicated Lavatory [all of CO's intl birds have a mid cabin lav which can easily be reserved for Y+ passengers except for the 777s]
Slightly better dining experience with real silverware and glass cups, but same food with snack basket services that consists of chips, candies, fresh fruits, etc.
More comfortable seats with more padding and the seat reclines like DL's current Y seats where the bottom moves forward. I think that is far more comfortable, because when you add in more recline your body naturally will slouch down the seat a little.

4-6 rows will easily do the trick...