I've always been a fan of this site since the CO days ... When the merger started and I had to use united.com, I was unimpressed. Back at the original merger time, I remember a lot of UA flyers complaining about how much they hated CO's site. Now, several years in, I read this thread, and the near-universal love for the website is fascinating. (And accurate, IMO!)
The features and functions of the current site are definitely better than any other site - AA, Delta, JetBlue, etc.
It is 'old world' design but that's a positive if you ask me. It's simple, easy to navigate, and presents more information than anyone else.
I don't know of any other airline that lets you see where your plane is coming from. Or even shows you the ship #. Or that lets you see the seat map right up through boarding. Or the upgrade and standby lists.
All of those are features I've come to rely on, and on the very rare occasion I'm on someone else's plane (usually because I got OAL'd) -- I realize how lucky we are.
Leave the danged website alone, please!