I'm going to try to sumarize mi opinion as much as I can:

1.Story: I think the concept is really original, It was about time that someone used it for a manga. (but i can't avoid to remember Mirai Nikki)
2.Character designs: It's not very good, it's very generic for me, but it's alright , I guess.
3.Character development: Well, it's kinda short for some of them, but I don't care about most of the manga's characters so I dont mind it.
4.Character personality: The protagonist has a personality that I really love, he looks like he is a sweet, inoccent boy, but in the inside, well, I won't spoil anything, but it is really nice, every character has a side that you won't expect.
5.Art: I love it, but the style is really generic.

In conclussion:
You should read Dead Tube, if you like nicely done gore scenes and awesome character development, you will enjoy this.