I actually agree with the OP's premise - that it's almost always a trade off. More "warmth" in the upper bass ("fullness") tends to obscure resolution in the lower mids to some degree. I also agree with Viridian that tone trumps all.
In my main system, I employ traditional, dynamic speakers from Merlin - which maximize resolution at the expense of (a bit of) fullness/warmth, and Verity - which offer more fullness/warmth at the expense of (a touch of) resolution.
Some A'goners seem to find the Merlins too "lean", but it's rare that I have a problem with their tonal balance. On most material, they're great. Same with the Verity: It's very rare that I'd ever crave more resolution. Yet, side by side, each speaker does illustrate the other's strength and weakness.
Dipoles and omnis can skin the cat a different way. Purportedly, the lightweight drivers of a planar (I own Maggies, too) provide resolution, while the reflected energy provides a sense of fullness. If an omni (eg Ohm) is voiced a little lean, you get a similar effect; resolution fleshed out with reflected energy. Some might argue that the latter (reflected energy) ends up obscuring the former (high resolution direct signal), but IME, that's highly room and set-up dependent.
All three approaches have their appeal, but most often I end up trying to split the baby with the Ohms.
Just MHO.
Marty