Except for all the annoying New Kandorian (gee, that name sounds SO close to New Kryptonian that one might think they stole it from LnC) plot lines
I think Kandor is Superman canon. I'm not a comic book expert, but I'm pretty sure that Kandor was a bottled city that Superman rescued from Krypton. But I'm fuzzy on the details...
Ultra Woman Andreia filled you in on the Kandorian details, but I meant more the use of "Kandor" as opposed to another or original name not starting with K. The New Kryptonians, The New Kandorians. Too similar, IMO.