Keep in mind that the VOD is content
already downloaded (as files downloaded, not streaming video) on to the other half of your HDD. That is why you can watch it instantly from the beginning and may have limited time (usually 24 hours, but it could be longer is some cases) to have access to the ordered VOD for finishing where you left off or replaying the entire movie at no additional cost. It is all ready for time shifting, if you will, but for a limited time.
The 222K has NO HDD, and, therefore has no VOD capability, but, as explained in a previous post, does have access to PPV, which are live streaming video on a number of channels to allow for the most opportunity to view from the beginning.
None of this relates to the movie or TV content via the internet called DishONLINE, yet a 3rd type of service for you 722.
ASFIK, the only advantage to the VOD is that, because it is already on your HDD, you may immediately watch the movie from the beginning rather than waiting for a PPV start time. The VOD behaves like any other recorded event on your DVR. This may make a big difference if you have guests who want to watch the movie immediately, and being a good host--not a cheap one

--are willing to oblige. Also, another advantage is that all the movies for VOD for HD DVR's are all in HD, while the HD live streaming PPV is comparatively limited in offering several start times to watch from the beginning. And, lastly, VOD is currently the only way to watch a movie in 1080p if it is offered. It is kind of a stretch finding advantages to VOD over the $1 cheaper PPV's. In my view, it is only worth it if you want a 1080p movie.