the big one: how do you choose speakers? By what features, data?

Haven't thought much in depth about specs and the sound of a speaker but I doubt that can be used as a workable guide. Speakers can measure similarly and sound vastly different.  

I don't have the music-speak for it, but to me (after 45 years of listening) it is all about how the speaker 'releases the notes'. Some may sound 'lightweight' and still measure like fat or dull-sounding speakers.  And, sadly, not all speaker lines have guaranteed consistent sounding models...but most seem to have their own sound.

I'd say try to hear as much as you can and take notes on general sound quality. Amps can affect this somewhat (might not hurt to note the amp you heard driving the speaker you auditioned). Buying an unheard speaker is a lot larger crapshoot than amplification or source. I only bought unheard, used D2s because I knew exactly what D1s sounded like in my room and knew the only difference was the additional bottom end. That was not a gamble.  :-)  

I'd suggest reading reviews (and lots and lots) as a better way than specs to arrive at potential speakers to try to listen to. It takes time but when you start to understand different reviewers' biases it gets more informative. Specs can sometimes tell you what to stay away from.    Have at it!

Speakers are very simple devices that have to obey physical laws like any other transducer. The only other consideration that is as important is the room you are putting them in. This assumes your goal is accuracy, reproducing exactly what is in the recording and presenting it in a manner that could be thought of as realistic. There are certain types of speakers that because of their physical characteristics do this better than other types. It is these physical characteristics that one needs to pay attention to. 

@mijostyn what are "these physical characteristics"?

That's what I am looking for, quantifiable things that show up in the specs.

@grislybutter , its an important factor, no one wants to spend XXX amount dollars on something and its ugly, you have to stare at it.  For me sound will be sound, how detail and refined will also depend on the amp and souce.  Call me shallow and maybe its me.  I have enjoyed listening to my speakers, the Silverline Sonata II are growing on me each day. 

@webking185 

I think there is more to looks than just looks. Everything (or 90%) is encoded in the looks. The company's DNA, priorities attention to detail, the type of sound they want to accomplish, etc. Unless it's a DIY speaker, I think it's like wine, you can tell the region where it's from based on the looks, and the year.