They are brand new.. Oct 29th was the announcement. Therefore I am sure there will be much testing in the future, and judging by the fact that they are 100% pigment inks, they are more archival then Epson K3
Also about voiding the warranty, not true. Read this quoted from John Cone.
On replacing EPSON inks with another brand The number one concern and fallacy about replacing EPSON inks with a third party ink is that it will void your warranty. This simply is not true in the USA because consumers are protected by the Sherman Anti-Trust Act which prevents a company from voiding equipment warranties when another brand of consumables are used in conjunction with the hardware. And The MAGNUSON-MOSS WARRANTY IMPROVEMENT ACT even goes further to strengthen the use of third party inks. It specifically states: “© No warrantor of a consumer product may condition his written or implied warranty of such product on the consumer's using, in connection with such product, any article or service (other than article or service provided without charge under the terms of the warranty) which is identified by brand, trade or corporate name" Actually there are many compelling reasons for using another brand of inks in your EPSON printer. Certainly cost is a consideration. EPSON Brand ink is expensive. If you can save 30% or as much as 80% on the cost of ink, the savings in a year can add up to the cost of the next generation of printer. Another reason however, is that often third party companies are able to produce an ink which is more conducive to your application. For example, EPSON needs to compromise when it makes inks. It has to satisfy the average consumer. I sell inks such as my monochromatic inks which produce the highest standard for black & white printing. This is a no compromise product. I also sell inks for my good friends at Media Street who makes an excellent color pigment ink which can be used even in older generation printers. Many of my customers resurrect their older generation printers to use with archival pigment inks. EPSON does not make their newer ink technology for their older printers. So this is also a great reason to buy third party inks. It can mean the difference between buying a new printer.
Fine if you don't mind voiding your warranty (or using inks that have not been tested by Wilhelm or others for longevity)