My girlfriend's looking to start up a homebrew space fantasy campaign when our run of the Emerald Spire concludes, and I'm hoping to hear people's thoughts regarding the various available rule systems for spaceship combat and travel. I don't know the specific of elements she's looking to include, but she's certainly leaning more towards 'fantasy, but in space' as opposed to 'sci-fi with wizards,' if that makes sense. The Big Three seem to be Starfinder, Starjammer, and Aethera, and as I've got a bit more time than she does to pore over rulebooks, I've already developed some impressions as I help her decide which direction to go, but having done no playtesting and very little theorycrafting, I'm hoping we can find more guidance here. Here's what I've gleaned so far.
• STARJAMMER: The feeling of Starjammer is the best for what we're trying to do, but a lot of the rule elements feel to sparse (designing customs hulls, available weapons or engines) and while I like that ships and components have GP values, it doesn't adhere closely to the WBL chart, has strange assumptions built into it, and overall offers little guidance on how to balance ship encounters well. I'm not so confident on the combat rules being as well designed as the other options, and I also think the element of "each ship component is magical and doesn't require external power' veers to far off of the flavor of Space Fantasy we're looking for. On the plus side again though, Starfinder compatibility is coming to Starjammer very soon and these biggest complaints might be cleaned up within that system.
• STARFINDER: Very thorough and complete rules, with a lot of thought put into the options even if they are a little off our target thematically. I admittedly have had little time to leaf through the book myself so this is more hearsay, but the math seems pretty poor (anyone following has heard about the DC 70 problem) and some maneuvers are noted as redundant. I also don't like that ships are entirely divorced from player wealth, and it seems a lot of flexibility is lost to make balance super easily (no rules for an NPC crew, tier is always equal to APL, ships DON'T become easier to use the better and higher level you are, ships rely on tier for piloting maneuvers much more than physics, etc.). Also, would require some amount of conversion to use with Pathfinder characters.
• AETHERA: This is probably my favorite of the bunch: space fantasy flavor with power requirements, ships have a financial cost but also CRs for easy balancing, and the combat rules offer players a lot of agency, and yet seem to have had the fat trimmed from them. I do have a couple gripes though: the selection of hull options is a bit limited compared to the other two and there aren't any guidelines for creating your own, as well as within the hulls you are locked to placing equipement in 'hardpoint slots', which is only compounds the frustrations found with limited hulls. The other problem is that Aethera ships do not have any guidelines for FTL travel (as the campaign setting is an inescapable star system) and I wouldn't know where to begin getting that right.
So what are everyone's thoughts? Anyone see a genius way to hack the best pieces of each together? Should we just bite the bullet on Aethera and add what we need, or see if some homebrew fixes to Starfinder's odd design choices crop up in the next month or two?