Now the problem was that when a critical mass or ravens was attained, the amount of energy stored by all the ravens no longer meant you could only use it defensively, but you had enough energy to constantly spam the abilities, and the ravens became this crazy flock of unit that you could no longer engage with anything.
So Blizzard did what needed to be done and reworked it. Unfortunately, when they announced the changes I was very disappointed with the new abilities concepts, and they soon proved to be almost useless anyway. The raven isn't a zoning unit anymore: the repair drone is a non-factor in an actual army fight, anti-armor missile damage is too low and the armor debuff is a gimmick, and interference matrix role is niche because it can only disable mechanical or psionic unit and the single target make the energy cost as well as the apm cost too prohibitive (you have to target every important enemy unit compared to throwing a pdd and be safe against most form of damage)
Now if we focus on each of the new ability and try to judge their design regardless of current efficacy:
The repair drone: I actually love the idea. Bio has medivacs for healing during combat, why mech unit wouldn't? Yes, SCVs can repair, but they either do it at home after a fight, or you pull them with your mech army, but you're usually better off sacking them to have more army supply, as we all know workers become dead supply in late game. The repair drone brings another interesting dynamic to ressource management. In late game scenarios, protoss, zerg and terran bio units all have a way to go back to full health with either time or energy: protoss regenerates shields, zergs units slowly gains hp and queen can speed up the process for energy, finally bio units can get healed by medivacs for energy.If you were using mech as a terran before 4.0, you had to spend minerals and gas to repair your units. While it isn't much, in late game scenarios where bases are mining out, it can become a problem. The repair drone fixes that. Now if you buff the repair rate of the drone, you make it functions closer to the old PDD as a zoning tool, while not reaching its bullshit level as enough dps will always negate its repair rate.
The anti-armor missile: So this is the new seeker missile. While a flat damage nerf was necessary, I believe 30 is too low. To make the ability more interesting, Blizzard added the anti-armor effect, which I hate. I don't think a debuff spell has any place in a game like SC2, this isnt WoW or a MOBA. It's confusing, not intuitive at all and it doesn't fit with the raven's role. Ravens always had synergy with mech because of the abilities but also because of the soft lock created by the need for tech labs on starport (too gas intensive for a mineral focused comp like bio). As every mech unit except the cyclone are low attack speed, high damage, the armor reduction is almost meaningless. Marines benefit from it the most, but a marine/raven comp is impossible for the reason I just mentioned. So remove the anti-armor effect. Damage only is too boring? Fine! Make the seeker missile a killable unit Think of it as an automated flying single use widow mine. You could still split or run from it like before, but now you have a new form of counter play. And since seeker missile do friendly splash damage, you could use it to your advantage. Someone massed 15 ravens? Blink 5 stalkers under it when the seeker missile fires and watch 15 ravens commit explosive seppuku. Now that sounds more interesting to me than "this unit has lost 3 armors points, attack it quick before the effect disappear!"
The interference matrix: Right now the ability isn't really an issue because it's mostly not used. Although with the next upcoming buff it could become very powerful, and to me even more bullshit than mass seeker missiles. Yes, mass seeker was OP and annoying to deal with, but you could always disengage or split properly. Interference matrix offers almost no counter play, and that's generally a big no-no in SC2. There is a reason we moved away from anti-micro spells since WoL, it's too easy to abuse and feels incredibly frustrating to play against. Remember the instant cast time, 8 seconds duration 100% slow of WoL fungal? What about the instant cast, giant double time warps that would inevitably appear out of a mothership core during the golden era of hots blink stalkers all-ins and would render any micro basically useless? Or the worst offender of them all, the archon toilet? They were either removed or heavily nerfed because they provoked game ending moments and a lot of the time, there was no way to avoid them. I could be wrong, but I feel this is the kind of ability interference matrix will inevitably become if it starts being viable.
My hope is that regardless if you agree or not on my proposed changes, the thread will spawn meaningful discussion and maybe give Blizzard some ideas on how to reshape the raven, a unit in dire need of a new identity.
TL;DR Keep the repair drone and buff its healing speed to be meaningful during army fight, but don't turn it into a mobile shield battery. Reintroduce the auto-turret in its new less harass heavy, more defensive oriented state. Get rid of the anti-armor debuff for the missile, buff damage slightly but not to pre 4.0 level, make the missile killable to offer exciting counter play opportunities.
My apology for the less than stellar writing, it's now 5am here.