Hellsing Ultimate, a remake of the original(Read my review) series with more content from the manga which took 7 years to complete. It ranks as one of the slowest anime releases to date as it was only 10 episodes long and around 50 minutes for each episode. The slow release was not because the manga was not completed, it was slow because they wanted to make sure the quality and action was as badass as it could ever be for each release.
The original anime was 13 episodes long and it traveled down its own road to created and ending for itself, the anime it very much awesome overall but it is not canon which was a problem for fans of the manga one can compare this to Fullmetal Alchemist and Fullmetal Alchemist: Brotherhood as it is very much the same, when hearing about Hellsing Ultimate it made for a good hype and fans got really exited to hear it was in the making.
Let me start of by saying that compared to the original Hellsing Ultimate it a lot more dark because of the use of shadows and playing with the colors to created a world of more dramatic feeling, chaos and darkness that Hellsing should really be, you will quite early in the anime get a feeling that ell has been released and it is hear to devour everything the darkness touches. However, the only reason i am watching this is because of the cool factor because even if this version of the anime is following the manga the fights and explosions is the only thing i believe is worth watching. If you want to find anything deeper in this anime you can try to look as hard as you want and still will not find it.
What you can look forward to is that Alucard is as badass as ever, he is basically a god-level vampire that will kill everything that stand in hes path with that psychotic smile on hes face. The humor is also still top notch if you remember that because even if Hellsing is a dark, gloomy and serious show it has a lot of content in it that will make you want to fall down on the floor laughing, a good example is when Seras is trying to stop Anderson and Alucard from fighting by leading site-seeing elderly people right between them, or when Seras is checking her breast in the start of the anime to se if the hole that was there is gone or not which is quite amusing.
So how is this compared to the original? As mentioned you should watch it for the badass fights, good quality, humor and awesome explosions, enjoyable and unforgettable but do not except anything other then that.