Marlboro,Gallo's speakers focus on their looks vs. any pretext of sound engineering so keep that in mind when you see such a design. Unless Gallo is operating in a different universe than we are, they the elements of acoustical physics still apply to his designs versus the rest of us.
The intermixed spacing of woofers and tweeters is still subject to the same combing concerns as more conventional arrays. This is especially the case for the woofers. The center to center spacing between the woofers has to be at least 8 inches apart so figure on what such a spacing will impact combing from the woofers. This combing isn't a good thing by any means. The tweeters are likely ribbons so they will be less apt to exhibit combing effects if the vertical plane radiation overlap is somewhat limited. Short ribbon tweeters do have more vertical plane overlap vs. longer ribbon versions but the overlap tends to diminish as frequency increases which reduces combing as I explain in my white paper.
While Gallo claims no crossover, the low pass filter on the woofers is part of a crossover per se. In reality he is using the acoustical roll off characteristics of these drivers and the low pass filter on the woofers to effect a crossover. Line arrays with low order crossovers tend to have more issues with interferences and combing so I would not suggest that this design concept is worth of emulation.
Jim