Gonna chime in with Trashman. SotS is a great game. I just upgraded to the Complete Collection and for me it gets the balance spot on. Games like Birth of the Federation became swamped rapidly in just brain-numbing planet facility building, SotS has comparatively very few micromanagement features. You have an income, you assign a certain amount of that to research, you save the rest or spend it on warships, starbases, freighters. Planets populations automatically fill up to a size limit, look after feeding themselves, and automatically terraform to your race's ideal. All you need to decide is how much of the planets resources are devoted to trade/commerce or are available for ship/infrastructure construction. There's research level based diplomacy, ceasefires, NAPs, trade agreements and alliances. But everything is mostly built around combat. THAT's the reason for the detailed turret modelling and hit detection; because it's the core of the game. Sure there's enough there to enjoy auto-resolving every fight and simply managing things but the game will move very, very quickly that way. It would be, to a fairly similar degree, be like playing Rome: Total War and skipping the battles.
The model design of the human ships is core to the human's technological backstory (the large ring around the engines). In regard to some people's opinion of their gaudiness, it was a concious design choice, they didn't want to go down the dull grey steel look of 'realistic' thinking.
The voice acting didn't bother me much to be honest (though there were certainly one or two very dodgey lines). I'm not looking to the VA in a 4x game to build much atmosphere and to be honest I thought it was fairly passable in SotS. Apart from a few scenarios that set the games initial starting conditions and objectives according to the universe lore, the games are all freeform and unburdened by the need to adhere to story. Again I think it work's for the game, I've played others where an included story works equally well, it's simply a matter of opinion, and maybe a little open-mindedness.
That however, is not to say there's no story or background. As Trashman said, it's actually got a really indepth universe, developed by the writing team (primarily Arinn Dembo) behind Homeworld (& Cataclysm) and (quick recheck) Groundcontrol (haven't played), and Arcanum (hmmp, didn't see that before. Definately a credit). I would very strongly advise visiting their forums
and looking around for posts or replies by Erinys (Ms Dembo's handle), especially in the SotS subforums, 'The Races', and 'The Ships'. My only complaint here is that it's not gathered in one location. There was even a 'mini'-book (300 odd pages) released in the first expansion, a few chapters of which are available to read. Unfortunately, I've not read it but it shows the thought that's gone into this. Personnally I can't wait for the sequel, at least partly because of the backstory.
Trashman; I'm a lurker over at Kerberos so I'm guessing from your passionate posting here that you go by the same name there? You play multi at all? Never tried myself but I must get into it.
One warning I will give; they (Kerberos, or almost exclusively Mecron, the lead designer) can be pretty wankerish if they don't like the implications or tone of a post so either lurk like I do or word it well.
Now go and get it!