Yeah at first It seemed to me that they were dying easier in a game with friends, all 3 of us could swear assailants had been secretly weakened.
But next games, na, was just our imagination.  Jav LRM's are better than ever due to the massively buffed tec economy(which is result of the black market changes) and nerfs to other races eco, particularly vasari's(again, result of the black market changes).
Assailant spam is basically gone, but the whole vasari race is hurt so that's a bad indicator.  If the market was fixed, it'd somewhat still be here.  But assailant spam exsisted before due to Skirmishers, sentinels, and carriers not being an option.  Skirmishers where Vasari's primary early game unit, and it was perfectly balanced how advent could counter them with much cheaper and HALF the supply defense vessals that killed them 3.5:1, and cheap rather effect scouts if you didn't want to tech or spend crystal/metal(Though, not as good a counter.  They kill them 1:1 I think? and are cheaper)
Personally what I would do is have all the costs revert back to 1.02's EXCEPT for javs (275/45/25 is fine for them), all the LRMS supply increased by 1-2(Something like JAV/ILLUM/ASSAILANT be 6/7/8, or 5/6/7[yes, illum 1 less than assailant ~_~ Illum is so much weaker than them]), jav range reduced(they.. outrange.. repel.. so many abilities and ugh.. so much you used to counter them before).  Make Tec need akkan to out-range repel, that's fair, some strategy and thinking element there. ;/) Making people have to upgrade fleet supply which bleeds their credits tends to work better than increasing the actual cost of a unit.
-play with their armor type some so that they are more easily destroyed by some things IE:
*have antiverylight do 150%(up from 100)
*antilight do 250%(up from 200, will boost both fighters and scouts damage against them) Or really, It'd be better to just buff scouts DPS to 4(So they'd do 8dps to lrms up from 6), 5.5 for vasari's, and buff fighters damage by 33% DPS.(How much do you see tons of fighters even for ADVENT for higher level play?)
While on the subject, bombers should have their survivability increaseD(but fighters remain the same).  If someone has enough they should be able to overwhelm flaks.  Currently it takes something like 6 carriers which take 2-5x more metal/crystal each than flaks to overwhelm the flaks with bombers.  Taking something like 3 would be better.  Fighters, on the other hand, should continue to be easily destroyed easily by flak just as they are now.  Just bombers need a buff vs flak IMO.  Flak currently counters bombers far better than any other ship counters another, when bombers are supposed to be SOMEWHAT better against flak?  They have antiveryheavy damage type(flak are heavy, close), and bombers are light armor(not verylight like fighters).  IT seemed like the right idea to make them more survivable and flaks be better at anti-fighter than anti-bomber, but it's not quite how it should be IMO.
*capital do 100%(Up from 75.  Why do caps do 100% to like everything but lrms?!..) 
*OR give LRMS their own armor type since so many ships share with light.
The big reason lrms are so good is that they're a good general unit, they do good against so much stuff.  Light frigs, buildings, caps.. common things you would encounter.  In the first week of the game light frig spam was big, after all.  So people spammed lrms..
I'd say reduce Anti-Medium damage to only do 50% against structures, but that'd make lrms too weak against heavy cruisers.  Part of why LRMS is so good is their destroying structures after they destroy the fleets.  75% of 11 dps of so many ships taking just 4 supply cap and are so cheap is still a ton of DPS.
-Buildings and HeavyCruisers need to stop sharing a damage type imo. :/  It'd be better if LRMS did 50% to buildings, 100% to Heavy Cruisers, not 75% to both.
Light frigs have less DPS than LRM's yet do 50% to structures vs  anti-mediums 75%.  Even with LRMS doing 50% instead fo 75% against structures, they'll kill structures fast, just less obscenely so.  They outrange the turrets, isn't that good enough anyways even if they did horrible damage to them?
One thing not taken into account with alot of people with these damage and armor types is that lrms are already starting out with 11 or 13 dps.  75% of 13dps is very similar damage to skirmishers base 10dps.  This is why they're still good against so many things.
Right now carriers don't make too great of a counter against lrms, even advents carriers, since lrms can fire on the move while they chase the slightly less agile carriers, buff to fighter damage would be nice, and scouts would be an alternative counter aswell.  Flaks are a good counter to lrms, (especially with 360 firing against a ship that turns so slow) but can't kill them fast enough before they do alot of damage.
And most importantly.. buy prices increased +50% and sell prices increased +100% or +150%.  It's allowing tec to spam ANYTHING not just javs while vasari is hurting.
Light frigs, capital ships, buildings, support cruisers, heavy cruisers.  (while not as good against heavy cruisers as bombers, they are just as good as light frigs against support cruisers which light frigs are supposed to counter due to their high DPS to start with.).  While what counters LRMs?  Basically just flak.  Scouts would make a decent counter to someone dropping LRMS in your base early as no tech req, and it'd give advent a boost(who is weakest vs lrms) since their scout is good and cheap, if scouts where improved.  And while they'd do good vs LRMS, they'd be bad against all else except trade ships and such, so they'd make a good counter unit.