Well, at least you'll get a similar kind of level handling - the same level of refinement or consistency not as much. Dispersion on 8" 2-ways often is somewhat imperfect with a typical narrowing below crossover. Their tweeter waveguides tend to not have a large enough mouth. (Or if they do like the JBL 308, they get a pretty naff woofer that doesn't have all that great level handling. The trusty Behringer B2031A, more or less a knockoff of an old Genelec design, is actually one of the better compromises, though not with the deepest bass or lowest hiss levels, and series variation seems a bit suspect as well.) You are best off having a calibrated measurement mic either way.So if size and weight is not that big a constraint, a good budget 7" or 8" will perform equal, if not better than a more premium 5" that is even more expensive with a bunch of DSP stuff, is that right?
Those have tradeoffs of their own. In the traditional "tweeter in woofer throat" kind of deal, the woofer shape is kind of a compromise between rigidity and treble dispersion, and their output is limited for the size as again the surround can't stick out too far and Doppler distortion becomes an issue. So the reports that the Gold 5 can't go terribly loud shouldn't surprise anyone, and the 8 is probably a better size to go for. Relatively few companies have mastered coaxes to perfection or close in general. KEF and Genelec, I guess, and the Kali coax is decent. That still took 90 years. This kind of coax works best when not much excursion is required, which is to say as a mid-tweeter in a 3-way. Treble dispersion oddities like an on-axis dip are not uncommon even then.And how about coaxial monitors? I saw people suggesting things like Tannoy Gold 8 or Fluid Audio FPX7, I think they're interesting but doesn't seem to be very widely used.
The "stick-out tweeter" coax variety (Fluid Audio, Presonus) does away with the Doppler concerns, but you have now created a circular resonant cavity in front of the woofer. Plus, while effectively moving the tweeter's sound origin back to coincide with the woofer via digital delay works on axis, off-axis it increasingly fails. This kind of speaker absolutely requires DSP to make work at all (for the digital delay and ironing out all the frequency response wrinkles to a halfway acceptable degree), and is an interesting approach, but tends to be rather quirky.

Fluid Audio FX50V2 Monitor Review
This is a review, detailed measurements, listening tests and EQ of version 2 of Fluid Audio FX50 DSP studio monitor/active speaker. It was sent to me by the company and costs US $149 each. There is nothing visually that distinguishes the unit from the original FX50 I reviewed a while back...

Coaxes that work well tend to be of the 3-way variety, and costly. ME Geithain (still a cavity problem, but I guess they're crossing over the woofer pretty low), Genelec Ones, KEF. If you buy a cheap coax, odds are you'll be throwing out the baby with the bathwater and pay dearly for your coincident sound sources by massive quirks elsewhere. (JBL 104 owners should be able to attest.)
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