Your Preference: Resolution or Fullness?

It's not an either or question to me. If it is full sounding but does not resolve harmonic and spacial information, this is a shortcoming. If it resolves spacial information and sounds say, lean or veers in that direction this is a shortcoming. We all hear things and value them to varying degrees. There are MANY other aspects to include besides the two you mention. Overall I want natural musical and spacial resolution and the low level information on the recording, natural timbre and tone neither overly rich but definitely not lean, natural dynamic contrasts. In other words, I want the music to sound convincing. The above items are ALL equally important for that to be realized IMHO. I find too much richness or fullness to become as fatiguing as leanness. It's all about balance and this is the hardest part.

Gotta do both pretty well and sound good overall. Lots of good affordable gear is capable of both.

The main keys to both together is often getting a good integration with room acoustics and an amp that is 100% up to the task of driving the speakers to the max. Power needed to do this with many modern speaker designs, especially at higher volume levels and with many modern "louder" recordings in particular is often underestimated.

After that is done well, the rest is more or less "fine tuning" the sound. Everything else will have an impact in all ways and no two combos are likely to sound exactly the same, so individual preferences come into play to a large extent, assuming gear is good quality in general.

I don't have to choose. I get both.