I read this immediately after finishing the original novel, and I enjoyed it as a companion read since it helped me more clearly visualize what had happened. I don't know if I would recommend that you read this instead of the original novel, since, obviously, it has omitted certain parts for adaptation purposes, but I suppose this could be a more digestible read, especially if you're overwhelmed by long descriptions of scenery. (I know I was by the time I got to reading about Mina & Lucy at Whitby). In general, I didn't have an issue with the omission of details, except for two moments when certain events were portrayed in a way that I felt suggested something very different than the original novel. But as far as adaptations go, this one is pretty faithful.
The only other downside is that the narration might get confusing by the end of the story. At first, this adaptation does a pretty good job of handling the epistolary style of the original novel, labelling the change of dates and indicating the shifts in narrator, but during the latter half of the story, I noticed that narration shifts weren't documented as clearly, and I found myself getting confused about who "I" was referring to, especially when they were all on the page and you couldn't just guess based off of context. This adaptation does distinguish between the different narrators by assigning each person a unique font associated with their writing, but I personally wasn't able to memorize which font belonged to which person while I was reading, so when explicit labels like "Dr. Seward's diary" & "Mina's diary" stopped appearing, I became confused. And I read this right after reading the original novel, so if I got confused, I can't imagine how much more confusing it could be to someone who read the original novel a long time ago or has never read it at all!
The characters generally looked much different than my own mental images of them and what I had expected, which isn't really a good or bad thing, but rather, just an observation. They gave Harker a very boyish appearance, whereas I expected him to look more mature. Lucy also surprised me because she looks so innocent in an almost infantile way. It's fitting since she is portrayed as "pure" and almost helpless for most of the story, but then she turns into a "voluptuous" seductress after she becomes a vampire, so her excessively childlike appearance is kind of disturbing. I found Morris rather unimportant and he didn't really leave any impression on me when I read the original novel, but somehow, I felt like he was much more charming in this adaptation, haha. On the contrary, I had a positive impression of Seward while reading the original novel, so I was stunned by how they made him look so weird in this adaptation. He has really long sideburns and looks a little crazy, which makes me wonder if there's a stereotype that doctors working at asylums have a certain "look." Regardless of his occupation, I thought of him as a lot more normal before reading this adaptation, lmao. Arthur was also more "princely" than I expected him to be. I'm not sure what I expected him to look like, since he didn't really leave an impression on me either while I was reading the original novel, but I definitely didn't think of him as "prince-like." The youthful version of Dracula was different from what I expected, too—they depicted him as quite attractive and even seductive/sexy, but I imagined him as more cruel-looking and not nearly as young. I think Mina was the only character who aligned with my pre-existing expectations. I think of her as less feminine and more mature compared to Lucy, so her more serious appearance, with her hair tied into a bun most of the time, matched perfectly with my impression of her.
One upside to this adaptation is that I felt like it actually made the final showdown with Dracula more exciting. Personally, I found the final confrontation between Dracula and the protagonists to be fairly anticlimactic in the original novel, but the mangaka said she envisioned the ending as something akin to a "Hollywood Western," and I completely felt that when I was reading this adaptation! It was almost like a shootout, haha, and there was definitely more of a sense of "action" going on.
(p.s. A warning for fellow arachnophobes—there are spiders in this story! Eek!)