RAM Rubric or Standard?

Main questions here is, what does one use to rate RAM better than the next.

I pose this question primarily because I am looking at a build but also for pure curiosity. I've been told by some that it is safe to go with whatever as there is not much variance in modules and you are just paying for a brand name. Others have told me that going with popular brands like Kingston and Corsair are worth it as they are more durable due higher investment in stability etc.

Example:

Company A's DDR4 3200 MHz @ 1.35V vs Company B's DDR4 3200 MHz @ 1.35V

Both companies' modules have the same timings and CAS latency and operate at the same voltage.
Now say that Company A is one of the "big time" companies (Corsair or Kingston) and Company B is a company that is lesser known for its RAM but still puts product on the market for a lesser price.

At this point it would be clear jump for the cheaper one. But say I have heard that it is safer to go with the "big time" companies since it is "safer". Would that argument hold any merit?

Just to make it real world, and to answer a question I've always had. What is the difference between Dominator and Vengeance other than an innovative heat spreader (on the Dominator).

Dominator Platinum @2666 MHz and the Vengeance @2666 MHz

The stats for both are:

Voltage: 1.2V
CAS Latency: 15
Timings: 15-17-17-35

The only difference I am reading about is their DHX cooling on the Dom.

Other than that is there anything that makes the $120 (USD) jump worth it?

(If there is anything painfully obvious that I am missing please point it out. Looking to learn.)

In you specific linked example of the two corsair sets it is the cooling that you pay for as the dominator is aimed at pushing the RAM further than it comes, overclocking.

On the others side of it I don't know the specifics but commonly most all ram chips comes from only a few companies like SK Hynix and Samsung so paying the extra is down to the quality of the underlying PCB/adjoining components and coolers and crucially the warranty, it should always be lifetime on RAM at this stage. And brand stupid stagnating loyalty.

Generally RAM is RAM. So long as it is from a reputable company and has decent reviews that say it doesn't come DOA or fail right away. I usually go with whatever is cheapest. Never had any problems.

IMO Corsair's RAM is overpriced. I'd just go with some $100 Crucial DDR4. 16GBs and no noticeable performance difference.