The distinction makes sense to me:
Warm-mod UA5 / Grace sound
overall feels smoother across the range
full, extended low end, but not as tight as below
nice meaty mids with an even transition to highs
extended highs, soft on attack but long on decay
Presence-mod UA5 / Apogee sound
overall feels punchier across the range
slightly rolled-off low-end, more "shape" to it in the mid-upper lows
mids more up front, punchier
more pronounced highs, brings out the attack in the highs
To my ears, this sort of mirrors the differences I hear between the Grace V3 and Apogee Minime. I find the Grace warmer, smoother, and fuller, more extended, while the Apogee has more "shape" to it, feels punchier in the deep lows and more pronounced in the upper bass and upper mids/highs.
Some people prefer the warm and smooth (some would say boring) Grace sound. Some people prefer the punchier, more up front (some would say edgier) Apogee sound.
:twocents: