I've seen it and I loved it.
And something new?
I think you misunderstand what this OVA is, the TV Series were based on the Hellsing Manga, but only the first 2 or 3 manga's were finished, so after the "valentine brother" episodes, they made something themselfs, because there was no material to work on anymore.
Ofcourse, it sucked big time, the characters they made in the later episodes of the TV series shouldn't have been made at all, its like DBGT, it made no sense.
Now, the OVA is here to fix all that, the OVA follows the manga very strictly, even art-wise (the art in the TV series is nice, but isn't the same as in the manga).
The 2nd OVA of hellsing, might feel old because it has done before, but I asure you, after this one, there will be a whole other story then that of the TV series, (this is because the manga is now up to volume 8).
In short, Hellsing OVA, is what the TV Series should have been.