It's a MAYBE for me, but in general I think this pack has great potential. MAYBE because I'm not in need of the space assets but it came with the huge pack as a must-buy and I'm not sure I'll ever use it...
Okay, the GOOD stuff of this package. There are 32 different templates to build your spaceships. Some give more parts that others, but you'll be able to make a lot of different fleets/races for your game. All parts are modular so you copy/paste them into your favorite editor to make that unique ship. The same pretty much goes for planets, where you can make almost every imagineble planet you want.
But there are also some BAD things. First off, this pack is made only for the big stuff - ships, spacestations (only 1 though), planets and suns and such. There's no interior for ships or spacestations. No cities for on your planets (though it does have a couple of nice other terrain features).
I've also read about people complaining about the effect animations not to match at beginning & end. This seems to be true, but I think you should (and could) work on it for your own project and customize them the way you want.
In general I think it's a good pack if you want to make a space shooter game with only ships and planets. If you want something in-depth with characters and such then skip it.