How tall do you like your images?

it ought to be entirely recording dependent. the more your system shows you differences between recordings, the better it is. cuz they are all different.

if your system and room have sufficient acoustics, space and signal path headroom, then any sort of mix present on the recording should be laid out for you to hear.

you should not consciously hear speakers nor the room. it should be just the music. some mixes bring the players into your room, others bring you to the venue space. your system should be capable of both at the highest levels.

if you play ’Whole Lotta Love’ at wrap 9 the sound should be everywhere; around, above and across the soundstage. closely mic’d concert grand piano should take up the whole stage. live recordings of a small combo jazz club should sound like that. full orchestral should be spread out all across and high and low......if the mic set-up and mix/mastering engineer did his job correctly.

height of players should be slightly different every time and scaled to the recording. one size fits all is a sort of distortion.

if it’s all one height, or one space, then you have work to do. there are so many variables to work out as to cause and effect. and certain driver types struggle to recreate some soundstages.

my room was set up to be able to do large scale music at the top level. took me many years to get that part right, and then more years to get intimate music to work too. it’s not a trivial thing.

Ya know, I just never thought about it. I mean, sure, when I'd go to Festival Seating rock concerts I'd make my way to the front of the stage and hear the music coming from above me. But in practically every other instance, I'd just care about the bigness of the image and width.

I agree with @noromance , and that seems to be the perceived height of vocalists on my system.

I prefer my vocals to be at about 6-7ft in height such that they are standing at a lifelike height or on a small stage similar to noromance’s post just previous to mine. That was my biggest gripe when I owned Wilson Yvette -- while the speakers sounded great (albeit too beefy for my room), the tweeters pointed down slightly to simulate a point source with a mids, and it made it sound like vocalists were sitting. No thank you!

I should also mention that my listening chair has a reclining function, which I like to use slightly so that hearing a taller soundstage feels more comfortable and natural.

Never gave it much thought. The image seems just right, like I’m a few seats away from the stage at a jazz club. Musicians seem life-sized with good stage width.

Kind of an aside, the top of your PC monitor should be at eye level, so your body's natural ergonomics, to look down, is satisfied.

I prefer the center image height to be at tweeter level which is slightly above my ear level when seated. In terms of width, my room layout isn’t ideal but I have the width to appear contained within the boundaries of the room versus going ’beyond the room’.

Basically, the imaging and height I prefer to be believable within my particular room.

That's an interesting question. My best friend doesn't hear my system very often, but the last time that he did, he complained that the images were too high because they were at a lifelike height. I believe the reason is that he is accustomed to hearing miniaturized images on smaller systems.

One reason why I like my LRSs and my previous MMGs is the large soundstage top to bottom.  And now that I put them on subwoofer bases they are even taller.  Maybe too tall now, now when they are close I tilt them down a bit.  Changes the high/lows balance.   It seems that treble is higher on the speaker.    

It's amazing how much the sound changes by moving them around.  With extreme toe-in and almost edge-on they just disappear and the sound seems to come from everywhere. 

FURTHER

https://upload.wikimedia.org/wikipedia/commons/thumb/2/22/Furthur_02.jpg/220px-Furthur_02.jpg

DeKay

Above!