Some of these seem to be "adaptations" only in the loose sense of telling a different story built around the same idea as a TOS episode. I think there was an earlier issue involving tribbles that wasn't the same story as "The Trouble With Tribbles" -- and their first original story in issues 7-8 could be seen as a thematic parallel to "Balance of Terror" since it involved the first UFP/Romulan conflict since the war, and did involve a ship crossing the Neutral Zone with warlike intent, although it was in the other direction.
I like this approach to their "adaptations": they're familiar enough to cue up recognition in the long-time fans while having enough new elements or perspectives to make it interesting for those same long-time fans. It also helps the comic creators to side-step the differing timeframe issue of when the prime stories took place versus when the nuTrek stories are happening.
The comic series itself has been improving in large measures by avoiding the more straight adaptation stories of its beginning run of issues. The creators have been very successful with their recent standalone issues (the Keenser and red shirt stories) and I'm glad to see them experimenting more with the format in the solo-focusing issues that will lead up to the new movie.
All in all, the Star Trek ongoing is a fun read each month and I encourage anyone that didn't initially enjoy the book to give it another try. In particular, I recommend issues 13, 14 or the most recent issue, 15.