Frankly, the U.S.A. minority variants below, are way behind most of the worldwide unbranded models that are largely on May, June and even July builds.
There appears to be a reluctance on the part of these U.S. carriers to pass on any improvement updates that Samsung issue. This could, in part, be because of the enormous amount of time, effort and money that needs to be invested by some of these carriers to incorporate all of their add-on's and firmware changes to the stock Samsung builds before they can be released.
These, "bugfix", releases are not from Android but, rather, from Samsung to fix problems with their firmware in the main. As you can see, only one variant, U.S. Cellular, has received updates on 4.4.2 whilst some International models have had as many as 4 or 5 since the beginning of the year.
This lack of updates from U.S. carriers is yet another reason that we are seeing complaints about issues that were, in some cases, fixed and passed on by Samsung months ago.
United States of America
AT&T SGH-i337 =
NB1 (FEB)
(AT&T firmware is not available or updated from Samsung sources.)
Verizon SCH-i545 =
NC5 (MAR)
(Verizon firmware is not updated from Samsung)
Cricket SCH-R970C =
NC6 (MAR)
C-Spire SCH-R970X =
ND2 (APR)
T-Mobile/Metro U.S.A. SGH-M919 =
NB4 (FEB)
US Cellular SCH-R970 =
ND1 (APR) updated from NAE (further updated to
NF6, see post
#54)
Sprint SPH-L720 =
NAE (JAN)
Canada
Canada (various) SGH-M919V =
NE1 (MAY)
Canada (various) SGH-i337M =
NE1 (MAY)