Originally Posted by
agehall
A final word of wisdom - stay away from codeshares unless you know exactly why you want one. They are not as "dangerous" within oneworld as they are within Star Alliance but it still trips people up at times.
There are several good reasons why one would want a codeshare every now and then, but given a choice between an itinerary consisting of prime flight numbers and one with codeshares, it's usually a safer bet to go with the former.
Just my $0.02...
Indeed, and considering the OP's rather obscure title, I was expecting this thread to be about one of the cases why you might precisely avoid codeshares. By contrast, as others have mentioned, luggage issues are extremely straightforward.