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

I used to sell hi end audio and the mark up on speakers is insanely high. I myself have gone the factory direct route. A few years ago I was reading a TAS review of the Emerald Physics EP2.8’s and took a chance. I bought from Underwood Wally after talking to Walter Liederman (owner of EP) for a few hours on the phone and I'm glad I did. Sold my B&W 802D's and never looked back. The EP2.8's were less than 1/2 the price of the B&W's and are a much more lifelike sounding speaker IMO. Axiom's Audio M80's or M100's are great value, well made and sound better than most brand names in their price range. I think they still offer a 30 day in home trial too. I have also had the pleasure of listening to the Hsu CCB-8's with the Hsu ULS 15 MK2 subwoofer. They are too big to be called a bookshelf speaker and need stands, but that package is truly a giant killer and efficient enough to drive with a smaller amp or receiver because the subwoofer is self powered. Dr Hsu demonstrates it with a little 10 yr old Sony receiver and the sound is truly astounding and not just for the price, astounding period. These speakers all use some kind of directional control of the HF's. The Hsu and the EP's use concentric mounted tweeters inside the midrange driver which controls dispersion and early reflections that can smear the image. I believe Axiom also uses a directional lens tweeter to control dispersion. Go to these websites, find a speaker in the price range for your budget and read as many reviews as you can. See if you can connect with an owner for a listening session. Emerald Physics is just coming out with their new line, and according to Wally they will be an evolution, not a design change. These are of course just my opinions.

@yxcbandit 

I understood about half of it. I am definitely not hi-fi, more like almost mid-fi.

But I do get your points about finding the best value, and focus on the characteristics that are important to me. Again awesome insight thank you, lots to think about!

No expert here. The most significant speaker criteria for me would be dynamics, dynamic contrast, and low distortion. As a HiFi enthusiast the speaker specifications I look at are:

1) power linearity:

2) efficiency:

3) dispersion:

4) directivity:

5) nominal impedance and minimum impedance:

6) low frequency response:

7) sensitivity:

Mike

You choose speakers "horses for courses", which is to say, speakers that best meet you requirements and simply, sound best to your ear. Bookshelf, Sub/sat, tower, panel are all viable options in your price range. Most speaker companies have series within their line, good, better, best;  bronze, silver, gold; premier, elite, limited. If you have a big room and like loud, then that will guide you to a big floorstander, like a JBL S3900 or 4367 rather than a small bookshelf. Conversely, one of the nicest systems I've seen recently was in an 11X14 spare bedroom and consisted of a pair of KEF LS-50s, a driven by a  Marantz 40 Integrated Amp. I love Magnepans, but you have to have both a Magnepan-friendly room that allows you to get them several feet away from both back and side walls and a very beefy 4-Ohm friendly amp.

In between you have the dual (or triple) 6" and 8" 3-ways. These are about as generally satisfactory of a speaker design as there is for your 'average' 200-300ft2 listening room, and from under $2,000/pr to well over $20,000 per pair they cover every budget point. They all have maximum output levels of aaround 112-115 dB and sensitivity usually 88-92 dB@1W/1M. They very dramaticlly in driver design (paper, kevlar, metal, composite sandwich) and tweeter (fabric and metallic dome, horn, AMT) and in cabinet construction (Vinyl MDF to cast unobtanium) and in internal bracing and detailing. But, the basic architecture remains - 2=3 woofers, midrange and tweeter in a vertical array. The reason is that this blueprint works very well across a huge expanse of requirements. How they sound varies as much as the pricetags, and some of the best values in audio fall into this category. From the the Polks and Monitor Audio SIlver 300 and 500 7G, to the megabuck Magico and Estelon and Watt, as well as B&W, KEF, JBL and a hundred more manufacturers. 

Once you have you basic requirements, then comes research and education (read what people say, and learn to read between the lines)  from which you create a shortlist that you can seek out and listen to and make your decision. 

Nobody in this hobby was born an expert. You need to sample as many speakers and combinations as you can. I believe that a good speaker is good on any type of music. If it isn't then it is coloring or detracting from the sound. For me my number one priority is vocals. If familiar female vocals don't sound real to me I'm out right there. Some speakers do a wonderful job on everything but the lowest audible octave (20 Hz to 40 Hz). That usually is the most expensive to reproduce accurately and typically requires the addition of a sub-woofer. Anything lower than 20Hz is felt more than heard, but can add to realism. Piano is also a good test of a system. If you live in an apartment you may not want that lowest octave. Bass is the most likely to cause a standing wave which is dependent on your room measurements. A standing wave can double or half the bass output, and sometimes you just can't relocate the speakers to eliminate that effect. Bass traps and corner treatments of acoustic foam can transform a room. The speakers are only one link in the audio chain. Trust your ears!