I purchased a metal table with acid finish from Kolkka 4-5 years ago. This is an extremely high end manufacturer and we paid thousands for the table.
Unfortunately, over the years, the table has become discolored where food/drink has come in contact with the acid finish.
Obviously, the table is well out of any warrently period -- however, I have been very disappointed with Kolkka's customer service. My experience is that high end manufacturers often go out of their way to fix a problem that are clearly their's, regardless of the actual warrenty.
I would warn potential Kolkka customers to ask a lot of questions about how robust the actual product is, expecially the finish.