I know this manga has not been fully scanlated yet (last time I checked only first volume) but I just bought all released volumes yesterday and I am in thirst of talking about how satisfied I am with DAYS. For the start, I am indeed a fan of Yasuda Tsuyoshi's (especially Over Drive *sob*) works, but soccer really never become my thing. I did following some soccer series in the past, however only Giant Killing and this series that was able to give me a real enjoyment of the sport.
On the beginning you might think that the premise is not that original and some of
the elements were already done by some manga in the pasts. However, I think the one who made me can't stop reading it is the characters (and its development). Tsukushi the main character, with support from eccentric and sport-genius Kazama, seems started as a typical weak and small MC which later surprisingly growing into a realistic outstanding player. And 'outstanding' here does not means that he has to be good in soccer; he got his own way. He is seriously a fresh character, who has a unique trait that can motivates his team mates. He is not that much of help, but the team needs him. And it does not look odd at all.
The Seiseki soccer club is of course a bunch of genius players, but they are also really stupid and hilarious. Moreover, each of them got relatively enough show time to make you feel attached to them. And unless you care, all the guys are good-looking, just not in the bishounen way.
I would not say anything about the art. It's perfect.
And yes, I really recommend you to start reading this and let's hope that the scanlation will be a lot more active soon.