codeshare question

Ok, I am flying on a CO codeshare operated by UA. Why I purchased the
ticket this way, I don't know. The codeshare price was the same as
the UA price. I could get ff points either way. There was a downside
too: there were some problems between the two sides during booking
requring a phone rep to complete the purchase, and I also had a hard
time choosing seats.

So, with price and ff points being the same, is there any sort of
upside to choosing a codeshare ticket? Even the CO rep couldn't give
me one.