What a joke! Apple has trumpeted how amazingly compatible the new Numbers is but spreadsheets created in V3 or older Numbers documents opened & saved in V3 CANNOT be opened or even read by older versions of Numbers!!! In our small business we have one computer that has upgraded to Mavericks and Numbers 3 just to test the updates. The mistake was made of saving an important shared access spreadsheet on the machine with Numbers 3 installed and now no-one else can access that spreadsheet & we will likley be FORCED TO UPDATE all machines to access that spreadsheet. Apple, this latest suite of updates to iLife & iWork rate as a total FAIL. So Apple please point me to where you tell users that their documents will no longer be able to be shared with users that do not have V3 installed? This sort of cr*p is as bad as Micro$oft was in days of old!