The other major limitations are that you cannot watch any on demand video and you will have a larger lag when changing channels than you would with a cable box.
The only way around the first limitation is to actually use a cable box for each input at the core. You can then use a USBUIRT to control it. This would let you pass commands (eg. up, down, menu,select) to the cable box to allow you to do VOD. Of course, when you use a cable box, you're stuck with SD at the moment.
The second problem is a bit more difficult to overcome. If you change your surfing habits to flip through the guide and then select your channel (a transition that's not difficult but takes some time to adjust to), you'll be fine. Otherwise, if you try to flip through the channels, you'll quickly get annoyed.
In the video, you'll notice that Paul put a cable box at his example TV to solve this problem (as well as the first). Don't forget that you can also mix and match (i.e. use capture cards at the core/on the network) and use cable boxes where/if desired).
I suspect you can use the cable boxes at the core's location as well to address the on demand issue only, though I'm not completely sure how/if you can route commands for multiple MDs to a device at a single location. I suspect it's supported, but I'm not sure.