A couple quick things I learned during early play. I played two games: Probably the first game every new person plays (Borg), followed by my favorite, underappreciated race in the series (Krenim).
First of all, the very fact that I could play as the Krenim was awesome (seriously, they showed up in one two-part episode and get a race spot? That's awesome). That being said, I noticed that they were... well, EXTREMELY strong. I found myself blasting through the tech tree, researching most technologies within 3 turns each, thanks to the Krenim research-emphasized unique buildings. This in itself wouldn't be a problem, except that during this time, I didn't actually do any colonization. I was more interested in seeing how quickly I could go through the tech tree than doing any sort of colonial expansion... but when I ran into my first race, I was pretty far ahead of him.
Take this with a grain of salt, though. As I said, my only two games were a Krenim and a Borg game. So aside from comparing the Krenim to the AI, my only other comparison is between the Krenim and a race that doesn't research.
Okay, now for thing #2. Now, this isn't a problem or anything... just more of a question. When looking through the races, there were two races in particular which I was looking to play. The first was the Borg. The second? Well, long story short, I was kind of surprised to find that Species 8472 doesn't make a guest appearance in the mod, considering both their iconic role as the menace to the Borg and in their great number of appearances throughout the Voyager series. I will grant that since Species 8472 didn't exist in normal space, it would be difficult to construct them in the game (my best solution would be either custom space stations or construction ships which would serve as the major economic and production base of the empire). But that's all side speculation, so I'll leave that to you to determine on the feasibility level.
Anyway, long story short, the mod is awesome! I'm having way too much fun! Thanks!