I've noticed that if your connection is fast enough, the "SD" pretty much looks HD enough. I can't see an HD version being that much better, IMO. It also looks fine on my computer monitor, where it would be glaringly obvious if it weren't HD.
On a computer... maybe. I run these through an App on my TV and there is a serious difference between SD and HD when you start running them on a larger TV, even good ones.
I'm just hoping when I check these out that the HD is only a dollar more like normal. If so, this is a sweet deal for some of these since I don't have to go out at night in this shitty Midwest weather.