The basic plot is fairly familiar: young man wants to become a mangaka, takes a job working for his favorite artist who turns out to be a young woman, they fall in love. And along the way, there are a number of jokes about breast size, there are beach and onsen episodes, there are jokes about moe culture... basically all the things that you would expect from a shounen or seinen romantic comedy. And Comic Studio does all of those things about as well as the next seinen rom-com.
All that being said, there are three things that distinguish Comic Studio from the rest of the pack:
1) Some attention is given to the actual details of creating manga as a team, as opposed to idolizing the "artistic genius working alone" myth that is often perpetuated.
2) The love story here is somewhat original, especially for a seinen rom-com. While told from Minoru's perspective, it's clear (to the reader, anyway) Ichiko has a serious crush on him from very early on in the manga. Telling a story from the perspective of the perused--rather than the pursuer, is unusual for a seinen manga and makes the love story seem fresh.
3) Ichiko, despite being 20, looks like a child. Surely this will appeal to some and turn others off, especially when it comes to the more ecchi moments.
So is Comic Studio a good, enjoyable manga? I thought so. It is certainly no worse than any other in it's genre, and I found the romance aspect of it particularly refreshing. I did find the loli aspect a bit troubling, which is why I don't consider this to be a great manga. But for a seinen romantic comedy, it's well above average.