Very odd...
The old limited-edition super-navy Cooltainer was a Sys-IV, and most of the Festool branded gray/green ones were, too. The Tanos-branded model is a Sys-V.
So the new limited-edition Cooltainer, which is just a plain-jane Sys3 M437, is pretty much the same size as the old Tanos version, but definitely taller than the Festool version.
There may have been a Festool-branded Sys-V size model in the normal gray/green, too, since there was a Tanos-branded version in that size, but most were Sys-IV's.
Maybe I should look more closely and more often at the pile of stuff I've been hoarding in my garage...