To clarify my earlier post:
I believe that EVERY small (or smallish) speaker must make trade-offs. I'd argue that it's a matter of physics; AFAIK, proper reproduction of the bottom octave + cannot be achieved from a small box. I actually like the decision that Ref 3a made, but it's still IMHO a compromise.
Ref 3a (in my view, wisely, as I stated in my OP) decided to optimize octave to octave balance. Even though the deCapo has better bass extension than most stand mounts, the bottom octave is MIA (as in virtually all small speakers). To offset that, the energy in the presence range and upper octaves of the deCapo is - to my ear - gently diminished. I believe that that's the key to the speaker's unusually neutral tonal balance.
Others may certainly disagree, but - to my ear - that benefit comes at a cost.
To my ear, a speaker's macro-dynamics ("jump factor") is largely determined by its energy through the presence region. In the deCapo, that's part of the region that is gently rolled to offset the missing bottom octave. It works tonally, but IMHO Ref 3a's design decision becomes a double edged sword: the speaker sounds very neutral, but dynamically polite.
Some may consider the deCapo perfect, but I don't. To the extent that reads as a criticism of the product, I'd only note that it's probably a gentler criticism than I'd make of virtually any other speaker of similar dimesions.