As of Vol. 7 Chap. 25:
This has a monster-of-the-week feel to it at times, and the harem aspect uses too many of the same cliches that show up in other manga (and anime) with harems, but overall I'm enjoying this series. 🙂
For me, the thread that ties everything together and keeps the story interesting is the developing relationship between Moka and Tsukune. Watching their progress as they become friends, learn to depend on each other, and eventually start to become much more than just friends makes this series a pleasure to read.
The stock situations caused by romantic rivalries get annoying sometimes, but that's more than made up for by the way the group members manage to be friends and stick up for each other despite their differences and occasional squabling.
Edit: I don't see Tsukune as a weak person. He may not have been born with super-powers like most of the people around him, but he is loyal to his friends, stands up for what's right, and willingly risks himself to protect his friends.
Edit 2: Finally had a chance to read the series all the way to the end of season one.
I enjoyed it all the way to the end, but wound up feeling let down: the series just didn't seem to live up to its potential. The relationship between the two main characters constantly seemed to be about to develop, but never actually went anywhere, and no real storyline or plot ever surfaced even though there were repeated hints that there was more going on than just random groups of monsters targetting the main character and his friends.
For me, season one left me with the feeling a lot of manga (and anime) leave me with: the feeling that the mangaka was working harder at dreaming up excuses to not tell the story than he was at telling the story. 🙁