Reborn is a series that truly understands its audience: the 'Shonen Jump' and fangirl (fujoshi) demographic. Like many series, it does succeed and does avoid the danger of a convoluted storyline quite well during its development. There is no doubt, like many of the previous reviews state that Reborn's art does drastically improve and while such quality is a pleasant surprise for a weekly manga, it gets better a tiny step by a time. Character designs are great which each with utmost care.
That being said, Reborn is not without its criticisms. The characters develop in different ways, but not necessarily good ones either. The typical shonen power up is done too quickly; a cheap shot and lackadaisical approach to techniques and ultimately serve little personal distinction. Even though these 'powers' are somewhat unique, they just seem cardboard cut out and the latest arc more or less confirms it with a Pokemon-like headline.
There is little teamwork which turns into stock one-vs-one fights that lead to a predictable outcome, and the only teamwork serves to bring up banter between the characters as a good attempt of humour. The fights require one to flip back pages just to see what is happening which is a problem with layout.
The biggest thing that seems to be done in a completely mismatched way is the environment and the plot. Utterly they couldn't be more different. Mafia in a futuristic military base in control of their petty dominance of their families? Readers may enjoy this as 'crack', but it just stands out as an eyesore, like a hippie tie-dye t-shirt in a zen meditation room.
So is Reborn worth reading? Yes if you do love your bishonen, a community that feeds of its own fantasies and confusing, but well drawn fights. As a shonen jump manga, it's one of the better ones, but like a shonen jump manga, expect depth and vivid storytelling that can only go to a certain extent.