Ultra 6 vs Ultra 6 Plus vs Pro vs Pro 6

Wirregar - My two NVX units purchased in the summer of 2010 (1 Business Edition and 1 Pioneer) are also on the discontinued list (as of late 2010) are still humming along just fine. Yes, the Ultra 4 and certainly the Ultra 4 Plus are faster, but I don't really consider them obsolete because of Netgear's consistent OS upgrade path, they are currently on 4.2.17 even though one came with 4.2.7 and the other with 4.2.9. If one totally croaks outside the warranty period (only 1 year left on the Pioneer), then I can simply pull the disks and insert into an Ultra, Ultra Plus or Pro, boot up and keep going.

If you see a unit that fits your needs and your budget, go ahead and purchase it. I would not worry about a unit being replaced, for as long as it still operates, it will be supported software wise. Case in point, as mdgm pointed out, RAIDiator 4.1.9 is in Beta and that version only runs on the Sparc units and they have been discontinued for over 6 months and the retail supply chain is almost totally empty of new units. I don't know of any other company out there still providing updates to the OS for a unit that is now 8 years old (the ReadyNAS 600) and there are still some owners posting on this forum.