Originally Posted by channa

As we're only a couple months away from that ominous day in March 2012, I thought it would be good to compile a list of features and functions that we'll lose when United customers move to CO's systems -- all in one place to better help our United flyers understand what features and functions we may be losing as part of United's move to SHARES. This way, many of our fellow UA travellers who aren't familiar with CO will understand what items they may be accustomed to that may not be possible going forward with the CO system.

Please feel free to chime in -- if you have anything to add, or if I'm incorrect about something, please post or PM me, and I'll keep updating this post to maintain it as a comprehensive list.