Long-time lurker, but I figured I'd throw my hat into the ring.
I'm surprised no one has brought up chapter 9 of Toole's book, which discusses boundary effects in depth (certainly not the only source, but it's a well-known book in this forum). Figure 9.13 includes measurements of the Infinity Beta ES250, twin of the Revel S12. As the book explains, "It was designed with on-wall mounting in mind, and considerable thought went into the physical layout and the crossover network to control the acoustical interactions of the drivers with each other and with the wall behind."
In an avsforum post I can't readily find, Toole also discussed the design of either the ES250 or another Harman bipole speaker, and the challenges of measuring it in an anechoic chamber by mounting the speaker to a boundary.
It seems plausible that the crossover network in the RS152 creates its own "EQ" to account for the boundary. It may be the case that the RS152 has other issues that the ES250/S12 avoided, but I doubt it's really the disaster that some comments here make it out to be.