When choosing new Speakers, what matters most to you?

That’s a very long question but for me, it is a simplified answer. I start my search comparing the specs, but that is not how I prefer to choose my speakers, those are just numbers on a fact sheet. I have listened to the speakers with the better specs only to walk away because the audio did not make me smile, it was rather a oh that’s not what I like. On the other side I chose speakers with the lesser speaks simply because their sound was brilliant or really fun to listen too, more lively than the flatness of the better specs, so now I only refer to specs to ensure compatibility with my receivers amplifier. Sound always first 

1. Price

2. If I've heard them and liked the sound, otherwise if I have a trusted friend who has.

3. Looks (size/dimensions)

4. Reviews

5. Specs

6. My other components and how they mesh

I presently have the JBL L-100 Classic 75th Anniversary Edition. I heard the L-100's, liked them, then with the new look and special edition that was it, then built my system around them.

In 65 years, I have never bought a non-American owned, non-Union made car. Not a whole lot of people can say that, but it’s one thing I can take to the grave and be proud of. At least I tried.

Used to drive a Toyota Camry. It had more American content than any other car manufactured at the time.

When choosing new speakers, what matters the most to me are the specs. I need to be able to anticipate how the speakers will sound in my room. Speaker design is not alchemy nor voodoo. It is a well understood science. Life is short, I have no time to listen to a speaker system whose designer could not bother giving me the specs. Then I listen to the speakers in MY ROOM with my electronics. If it pleases me I buy if not, NEXT. There are a lot of good ones to choose from. 

detailed specs are a great guide but they only go so far for me. i MUST be IN THE ROOM with the speakers, playing MY music ONLY, what i am familiar with. if it sounds musical but doesn’t image well, FAIL. if it images like 3D holography but sounds bad, FAIL. gotta be the whole package, with imaging AND great sound [with a notably luxurious never-flagging EASE] that never fatigues, never is edgy even with harsh-sounding material IOW it doesn’t make edgy-sounding stuff more edgy. the system must make low-level signals clearly audible with no straining to hear. my present system using Thiel cs.5 speakers does this, and before that my maggies did it. the energy 22 pros had it about like my thiels. the snell class A [revised] had it. a speaker i couldn’t afford or even have room for, the magnapan tympani IIIs, they had it in spades. so to answer the OP’s query, it can’t just be one thing. obviously, if the speaker is a 2-ohm power drainer and amp wrecker, it is disqualified no matter how otherwise splendidly it performs as i can’t afford a krell monster amp or its ilk. so there are practical considerations as well.