I will not analyze this OVA in terms of storyline, character development or animation/sound, since this is, in my opinion, just a recapitulative episode on steroids.
So, there are two possible situations in which you should watch these two OVAs:
1) for the sake of completeness
2) you don't have enough time/pacience to watch the original series and you need a brief summary because you want to watch Unlimited Blade Works or Fate/Zero or you want to play the visual novel (in my case :D)
As a recap episode, TV Reproduction does its job. However, I wouldn't recommend it to anyone who hasn't seen the original Fate/Stay Night because, being only 2 hours long, the storyline is very fast paced. Like I said, it's only a recap episode and shouldn't be treated as a stand-alone.