Should you watch this show? Yes.
The iDOLM@STER starts off as a good show. Nobody who paid any attention would call it great, but it definitely becomes a dang good show during its last third. It spends most of its time being very episodic and with a particularly misleading first episode (it seems that the show will be a reality show, but don't worry, it turns into a normal anime after episode 1), I can understand why some people would stop watching very early. But this show deserves some love.
The characters are all interesting in their own way, all of the ones that you get backstory on are very real and relatable, and none of them are so outlandish that it's off-putting. The problem is that there are 13 main characters. That's right. 13 of them. Between the twelve idols and the producer, and the less important-but-still-there trainer/producer and secretary, there isn't a whole lot of time to really fall in love with the cast. But chances are with a cast of that size, you'll find that type of character that you already like.
The only thing in this show that is definitely not up to par is the animation. Visually it's a little choppy compared to most other shows and anybody further than about ten feet away has almost no face at all. It's clear that a lot more care than normal was put into the characters when they are dancing and singing. Honestly though, it sounds worse than it is. The background characters are all as detailed as the mains, sometimes more so. This studio didn't skimp when it came to background characters, though their animals could use a little work. This is the only thing that I can really hammer the show for, however.
Okay, that was a little bit of a lie. Remember how I said this show was episodic? There are a couple of times where the writers decided that they didn't want to deal with realism and opted instead for an outrageous story. But that's only a couple of times. For the most part the stories are cute and relatable, generally the stories do a good job of helping you understand the way a character works or why they are the way they are. One of my favorite examples is Yayoi, the little orange-haired girl. This story not only shows you why she does what she does, but also shows some serious growth on part of another character in the show. Generally the show gives one episode per character so that you get a chance to bond with them all. Towards the end the show however, it gets a serious sense of continuity and the story becomes very good.
This show also does a good job of showing the not-glamorous side of show business. Granted it is still a glamorized version. Take away the meaningful relationships and the nice man in charge and the first half of the show is kind of what you can expect if you want to be an "idol." The frustrations that go along with it, the drama, the uncertainty, these are all shown in the anime. And the girls handle them in very realistic ways, more often than not. One girl is extremely shy, so she is extremely anxious about her first performance, and it's only through the encouragement of her producer and the support of her friends that she is able to overcome the shyness, for that show at least. The girls deal with the jealousy of watching their friends become more famous than they, and some handle it better than others. We see people do things that they don't want to do, but since it's their job, they do it with a smile on their face. This is show business, and it is portrayed very well in this show.
Now on to the topic of the music in the show. This is a show about idols, after all. The songs are alright. I really enjoyed a few of them, but none of them are amazing. However, they all fit the situations that they are used in perfectly and they often really drive the emotions of the characters home. So I cannot fault the show too much in this department. It does a lot more with music than most shows do, and with much better results, especially later in the show.
My recommendation is that this anime deserves a shot, at the least. The first episode does nothing but introduce the cast, once that is over, you get into the stories. Give it a shot, if you get to the end you won't regret watching the show, I can promise you that. I've never wanted to start fan-dubbing as much as I did when I finished this show.