Also you miss the ability to do OLCI about 33% of the time based on my track record with US codeshares on UA. US tends to mess up the e-ticket so that it gets out of sync with the PNR, and neither OLCI nor kiosk will work. TA at the airport checkin counter can fix it in 30 seconds, or you can waste 30 minutes on the phone with 1K web support in India who still can't fix it.

Otherwise no problems, miles post fine including RDM, EQM, and BIS/Lifetime. Except once in a while the US booking class doesn't get re-mapped to the UA booking class. A cheap US fare class like E might map to a UA class like T, and that's how it posts normally. However, I have had US deep-discount "G" class fares for UA codeshares, which are valid US classes for UA miles, stay as "G" when it posts with the UA flight number. G is not a miles-earning class for UA (it's a travel industry class), and I went through days of calls/emails to 1K before they finally fixed it up as the actual UA class (S, if I recall correctly).

Watch out for those two problems and you should be ok.