I have only just played a bit of I-War 1 and am completely surprised by how extraordinarily similar it is to the Battlecruiser games.
Maybe except somehow managing to be even more confusing and user unfriendly than BC.
Do the similarities persist? I-War seems to be far more mission-driven than any Battlecruiser game ever was.

(And yeah, if you don't know what I'm talking about, google for Battlecruiser 3000 AD - you'll find free release of 3000 AD and its sequels/remakes/re-releases, BC Millenium and Universal Combat)

You tried reading the manual and reference card?

I have, I also have read the manual for Battlecruiser Millenium (somewhat ironically, if you read one BC manual, you're good to play any game in the series). This is not a complaint about depth, difficulty, or any of that. It's just an observation.

On that note, I-War 2 needs a keyboard reference card, badly.

In what way is it confusing and user-unfriendly though?

For starers, bridge navigation could use a quick method of re-entering the station you're at. Then, global hotkeys would be cool as well, I know there are supposedly some but they do not work well enough. Next, HUD is cryptic and cluttered, especially compared to Battlecruiser's. I can understand using shortcuts everywhere, given the low resolution this game is using, but often the information I need is often spread over several screens.

I don't really understand your issues. Why would you need to reenter a station you're already in? F1 through F4 are the keys that select bridge stations. I don't really know what you mean by the HUD being cryptic or cluttered, as far as I can remember there are only a few elements, the reticle, the throttle/speed gauge, and any ships' or objects' brackets.

I've played both the I-War and the Battecruiser / Universal Combat series quite a bit. There are definitely similarities. In fact, I remember Derek Smart writing that he loved the first I-War game, but disliked the second. (iirc mainly because of the somewhat simplified ship-system dynamics and heavy story-driven gameplay of the second game).

If I were to make a (personal) list of cons and pro's, it would be something like this:

I-War series:
+ newtonian physics
+ friendly user-interface
+ very moddable (mainly I-WAR 2)
- no planet-side action
- no tactical meta-game (capturing stations, sectors etc.)
- no 'free-roam' mode

BC/UC series:
- no newtonian physics
- unfriendly user-interface
- not (really) moddable (some aspects can be changed, but no mods have really ever been made)
+ planet-side action
+ tactical meta-game
+ free-roam mode

I thought I-War 1's story was far more grown up and engaging than the bland I-War 2 campaign.