This is a fast and competent newsgroup downloading tool. It works quite well, the only gripes I have are, it won't automatically start downloading when you drop an nzb file on it, you have to tell it to. Also, it won't auto repair files using PARs.
What it does do, it does well and it is a pretty new program, so it probably isn't fair to fault it for not having the advanced feature of repairing RARs. However, starting to download files when you drop an nzb on it is something reasonable to expect at this point in development.
Considering how rock solid it is right now, and how well it does what it says it is supposed to do, I think this is a very promising tool for downloading files from newsgroups. It is very intuitive and the set-up is simple and straightforward. The only minor gripe about the interface is that it is a bit "Window-y", with letters underlined to indicate menu shortcuts. It just needs a little clean-up to make it more "Mac-like". The downloads are very fast, and it is able to open a user-defined number of connections (limited only by your provider).
This program hasn't replaced Unison for me yet, but if the developer adds repair functions, a "watch" folder for nzb files and makes the interface a bit more "Mac-like", it will. No program, not SABnzbd, not Nzb Drop, none will rival it then. Heres hoping the developer will add those features (and allow it to start downloading immediately upon nzb drop) and clean up the interface. It could be the best newsgroup downloading tool out there if those items are addressed (and it will then be worth the $20 asking price).