I had always avoided 'The Original Series' as I had always remembered it from glimpses as cheesy and poor (put it down to it being old). However I have been pleasantly surprised. The acting isn't as poor as I remembered and this season the actors seems to have settled into their roles. The only thing I believe that really lets the show down is special effects (it's heard for a situation to seem tense when some monster looks like a man under a rug), but we can't hold that against it since it was pushing the envelope for a TV series special effect of its time. So, it's worth a watch, enjoy.
It's a good job they remastered the space scenes from what I remember they were very poor, so it helped they gave them a bit of polish. The acting of Bones and Kirk are some of the worse I've seen, more so Kirk dreadful. Apart from that enjoyed watching it. For how old it is its quite a vision of imagination.
Having grown up with the original series, indeed the first colour TV we had switched on to an episode of Star Trek, I can say I would be enjoying this DVD "re run" in whatever way it'd presented, just happy to giggle at tribbles and sparkly dressed Klingons again.