Comparing the version numbers gives a good impression of how much of a maintenance burden RedHat is taking upon themselves. You can't simply presume that RedHat's 3.10 fork is missing any particular feature or fix from future upstream versions, but it's quite obvious that RedHat's fork has to be missing something by now, and probably a lot of somethings.
Enterprise customers care much more about stability than features. Backporting features is always easy, if you consider the amount of work needed to have enterprise level guarantee on their quality. Weeding out bugs in features is much, much harder.