A shame we have no Kipple of these
True...
However, if the goal is objectively the smoothest, flattest and most neutral frequency response then the Sceptres aren’t gonna win awards over monitors like Neumann and Genelec. I've performed enough quasi-anechoic measurements to tell you that for sure… I would say even the waveguide of the cheaper JBL LSR studio monitors produce much more remarkably smoother transitions in the horizontal plane. However, IMO, the sound of the Sceptres still is subjectively better than any of those other more budget oriented monitors — or at least the few ones I listened when directly set side-by-side together in the same room e.g. JBL LSR, Mackie MR, and Fluid’s coax. Although, with the Neumann KH120, eh, it’s kind of a mixed bag. However, this should not come of totally as a surprise given that after a certain level of relative smoothness and flatness in speakers, it's the other differentiating factors that become more important e.g. bass extension and performance at increasing volume, as well as perceived tonality which primarily is influenced by the on- and off-axis dispersion and room interaction.
I may have explained it in this thread or others at ASR before... that it is actually the narrowness or particular frequency dependent off-axis directionality (some could call it lobing or beaming in the more negative/pejorative sense) that “can” make these speakers actually sound less harsh and more pleasing than the far more consistently flat Neumann — I’d presume this is going to hold true with some Genelecs as well.
Weakest point of the Sceptres may be from the on-axis “forwardness” in some of the upper mid-range area (and, this most prominently affects vocals more) but, on the other hand, this on-axis peak really mellows out quickly off-axis.
In the end, a lot of this also becomes a matter of taste. From experience, I’d say the bulk of any offending, subjective or even measurably objective attributes should be modifiable or "fixable" enough with EQ — that is, if one isn't averse to playing around with DSP.
Let me be clear, though, DSP cannot truly “fix” the inevitable, inherent diffraction caused by abruptly interrupted geometry of that small horn waveguide. But, we can shape the response enough so that perceived magnitude of those audible effects or "coloration" becomes significantly mitigated or reduced to the point of being...
largely inconsequential.