Image precision is primarily delivered by the first-arrival sound, and is degraded by very early reflections from the speaker itself (including diffraction), and also by early room reflections, but not so much by later reflections unless they are too strong.
Envelopment or immersion ("you are there") is delivered primarily by a clear differentiation between the first-arrival sound and the later reflections, which means that early reflections are once again particularly undesirable.
Early reflections are not all bad - for instance early sidewall reflections can can make it sound like the soundstage is wider than the space between the speakers, something that most of us enjoy. But the same auditory mechanism which expands the soundstage to the outside due to strong early sidewall reflections also reduces imaging precision and in particular soundstage depth, so it’s a trade-off.
These are not the only things that matter, the time coherence of the speaker also matters. ("Phase coherence" is virtually a marketing term and imo usually means very little.)
So ime the IDEAL balance might be really good first-arrival sound, then little or no early reflections, and then a lot of (but too much!) spectrally-correct late reflections. "Late" within the context of home audio being "about 10 milliseconds behind the first-arrival sound". This can be accomplished with a combination of speaker choice and setup, and maybe room acoustic treatment.
One example might be, a pair of relatively uniform-pattern fullrange dipole speakers positioned at least five feet out from the wall behind them, perhaps with a considerable amount of toe-in to minimize early same-side-wall reflections.
The best imaging I have ever heard was from a pair of Supravox wizzerless 8" fullrange drivers, listening nearfield in a large room, with one aimed at each ear. Sweet spot was head-in-a-vice, soundstage was incredibly deep, but the presentation wasn’t "you are there".
Best imaging with more practical speakers was Earl Geddes’ personal three-Summas-plus-subs system in his dedicated listening room. This system also did an excellent job with "you are there", but not the very best I’ve heard. Sweet spot was exceptionally wide.
The best "you are there" I have heard was from a pair of SoundLab Ultimate fullrange electrostats in a large room, set up with maybe seven or eight feet behind them. Again, wide sweet spot (but not as wide as Earl's Summas, relative to room width).
Duke
yeah I’m a SoundLab dealer