I've opened like 74 superior caches so far... I JUST finished Alpha. Tactician, Firecrest have been done for a little bit. Tactician being the most important... but even it can be outdone by Barrets, Inventive, and 4 PC tactician... Though Relentless backpack seems to be the most popular. You use a turret and sticky bomb and no health skills. (5% of the damage your turret does comes back to you as health.)
Alpha is so gimmicky... and requires the last shot for anything on it to work and no signature from allies really hampers it too. Frankly, till they redesign it it will likely sit on an ult and never be used. There is a bit of salt in my opinion. Most of the vets wanted the return of the old alphabridge. (In it you got use of all six talents but the FAMAS, now bullfrog, broke it (badly) and they reworked it to bottom talent only (and no exotic talents). They need to keep the no exotic talents. An MDR with uncomplicated (bullfrog) and two other talents would be so broke it would be disgusting.
Firecrest is very meh also... Its pretty much a supporting role only and the fire turret isn't as responsive as the Gatling gun turret and allot of enemies will run past it and focus on you.
Hunter's Faith... The set has always been crap and six pc doesn't seem to help too much from what I can tell (I don't have a full set though) but I've heard of people doing mass damage with it... but till the GE event ends and the ambush damage modifier is removed we really won't know how powerful it is.
Anyhow, get the sets finished now... They have fixed crap sets and items before and they'll likely do it again.
I'm the proud owner of about 5 new MDRs this week... and I've even dropped a few.