No such thing as a "2014" model or any other Honda mower 'model year' as Honda does not use model years to denote differences and running changes.
Instead, Honda uses a version code called a K-number, which increments as changes are made. For example, the most-current version of the HRX is at version K5, which you can see on the serial number plate. K5 models have been in production a short while, so it is totally possible you might find a K4 or even a K3 version for sale. The changes are very minor in this case, mostly cosmetice and appearance. The K4 model gets a slightly different carburetor vs. the K3, for example.
Other Honda mowers (HRR series) for example, are at version K9, and have been for the past few years. A K10 version isn't expected until next year.
In another example, Honda's small 'suitcase' EU2000i portable generator has been at version K1 for the past 9 years, with no changes at all.