to be honest, I have, aerotech 1, battlespace, and aerotech2 but not a2r and the core books, tw, tech, to, so, atow
my preferred edition in a lot of ways is at1 (aerotech 1) because its effectively battletech in space
the things I like:
direct port of weapons tables, from the ground game so yes there IS a reason to mount an IS ppc vs a large pulse laser .....
I also like the old more locations for fighters and crit tables from that game.
with that said I don't actually dislike battlespace as long as you look at it being the space equivalent of battleforce.
where I really dislike the at2, and a2r is I feel that they essentially "threw the baby out with the bath water" if it had gone back to at1, and tweeked it from there I would have personally been a lot happier I think.
the fact that in bs, at2, and at2r, also core set the standard unit for fighters is the squadron not the individual fighter and the reduced and "generalized" locations also encourages "brick" building I feel detracts from the idea of the fighter, it also makes them in many ways TOO powerful IMO don't get me wrong when I am running the fighter swarm against the dropships and warships, Its kind of nice to be able to swarm them under, but as general rule I think its too easy.
if I was to design my own version I think I would take a page from "wing commander 2" and basically make warships and dropships conditionally undestroyable by fighters. they can be crippled, and made unable to do their jobs, but their "core systems" can't be eliminated readily by fighters, and I think one way to do it would be to implement a 3rd scale (possibly) and or tweek the rules for capital damage.
my idea would be to sort of use the idea of hardened armor RE capital scale.
I am ok with the capital SI providing capital scale armor that functions as "true capital scale" but I would make standard dropship armor back to standard scale.
how this would work in my idea is a fighter is standard scale, and flys up and shoots at a dropship, it can damage or disable systems blow up armor etc until it hits the "capital scale armor" once it gets to the "capital cores" all it can do is attempt to cause crits, and without all those tons of armor protecting the vitals this actually becomes possible, but the weapons can no longer cause "capital damage" directly, they can only do it as a result of effects on the critical hit table, and you only get checks when you can do in excess of 10 damage in a hit.
I would also make stations jumpships and warships have parts that are effectively immune to fighter damage, barring special case rules, random crit effects, and the like (so ramming could cause criticals or similar)
now to make fighters relevant they can go in and strafe, and attack /destroy standard scale weapons all day long, its the capital stuff that they have to get lucky to disable.