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

I haven’t read all the responses but I can assure you, that purchasing a Yamaha CR620 receiver for about $200-$300 and either a Legacy Signature III or Focus speakers for $1500-$2500 (all used but very durable/recap the Yamaha if necessary) will bring you fabulous sound at a very low budget cost. You can always move up in electronics but you will probably keep the speakers for decades (or until you can spend a lot more money). If you already have a decent preamp/amp, then the Sig IIIs are easy to drive, great bass and slam, gorgeous quick mids and spacious highs (rear tweeter). I use a 35 watt tube amp on the Sig IIIs in my living room. My main listening room Focus require more power with 6 12" woofers and lower impedance for tube amps, not a problem with the solid state receiver. that has good current/control.

Clarity

Tight bass

Synergy with rest of equipment

@fleschler

I think you are right about a Yamaha receiver- Ive bought several in different houses as the sound and feature set is good even at low cost levels. In my own world (as I do import both pro and hi fi ATC to the US), a pair of ATC SCM 11’s that are around 2K new gets you pretty much in right ball park. A reasonable receiver will get you the same sound as the studio most of the time, depending on room.

Some say we should seek tight bass? Maybe so, but this is HEAVILY influenced by the room. You can have a tight bass speaker not sound tight in many different kinds of spaces, especially reflective ones, square or rectangular with even dimensions of placement, hard floors, hard walls, low hard ceiling ones. Room "standing waves" can make one think the speaker’s bass is anything but tight and this is 100% room. [To know for sure, just take your speakers outside where there are no walls, and see if the bass is tight. Second choice, take speaker to a largest room you can get, set up in the middle away from all surfaces.] Ceramic tile or stone floors will mess up any speaker; a wall of glass will mess up imaging, speakers right up agains side walls will never image as well as they could, and the list goes on.

So in your listening room., shoot for uneven dimensions, no square or round rooms, no low ceilings, avoid glass in the room, avoid anything highly [acoustically) reflective in the room. Soft surfaces everywhere helps. If the room has any echo when you talk, it will be FOR SURE horrible for playback of audio no matter where you put the speakers.

Brad

@grislybutter  I wish I could help you more. I watched a bunch of reviews, but without the personal experience to back it up I can't stand by my words. I re-read the entire discussion and something stands out to me: you want some punch. So you want full-range speakers. Something like a KEF R3 (non-meta) will seem like an obvious choice at first, but the bass is a bit shy (bookshelf speaker by design). 

My advice: Go to Audiogon classfields. Tick fullrange speaker criteria. Sort by price. There are several standouts under $2.5k: JBL L200, Vienna Acoustics Mozart Grand Symphony, Canton Chrono SL, Neat Acoustics Xplorer... But I have no experience with those, just brand recognition. 

@kokakolia

I think I prefer three things in this order: warmth, upper midrange and details.

I think I have those from my current speakers - Evoke 20s so I would like add more presence, speed and disappearing speakers/imaging.

I’d like to stick with bookshelf, but you may be right. I have huge respect for Vienna Acoustics.

I will send you my list of 70 speaker brands, it helps me put things in context.