The original Robin Warriors (Yoroden Samurai Troopers) aired back in the late 80's so few would remember it really. To those who were/are fans and interested in watching past the battles with Talpa and that storyline, don't bother.
Mostly all of the OVA's are contradictory and extremely confusing to the original story. Add to the fact that these weren't dubbed until nearly 20 years after the original series. They got most of the OG actors back which is cool, but it's been so long they don't even pronounce character names correctly. IE Ryu which was originally pronounced how it's spelled (RYE-YOU) is now (RE-YOU). Not a huge deal but kind of annoying. Especially since again, the original voice actors have returned.
The story itself is completely flawed and ridiculous. After everything they've been through, the armor is now "evil" and their entire story is basically being retold through each part of this OVA. Some random lady appears from the netherworld claiming the armor has always been evil and plans to snare each warrior, also bringing with her an ancient text that reads their whole story before it even happened. We don't actually see anything new until the final part, which is new armor based on the virtues that their original armor was imbued by... which makes no sense? Maybe there is too many mistranslations or maybe it's just poorly written. It's long and not as bad as the Black Inferno story (even more stupid), but it's easy to see why this wasn't developed back when the original series was made.
If you're a true fan I guess it'd be hard not to skip it. I am a huge fan and this really tried my patience. Would be cool to see a remake or something though.