I wouldn’t use speakers pointed straight down, and aimable tweeters seem kind of gimmicky to me anyway: I want the crossover to be designed knowing the position and orientation of midrange and tweeter.
However, I also wouldn’t use toppled MTM speakers, including Revel’s with the toppled MTM and the old Infinity Cascade midwoofer (or an evolution of it). That is a terrible drive unit configuration for any loudspeaker.
If you don’t expect so-called reference levels, take a good look at Tannoy CMS403DC. These are little things with a gourd shaped cabinet in a ring. The cabinet sticks out a little from the ceiling, but they are aimable. In our old house we used a similar speaker for Auro/Atmos, Tannoy Revolution XT Mini. They weren’t world beaters but they were suitable to purpose and in practice worked just fine. There may be other 2-ways where the whole array moves as a unit, but I don’t know of them.
If you need something bigger bore, Monitor Audio has a line with a neat aimable concentric midrange-tweeter they call IDC. At woofer-mid crossover frequencies relative orientation matters less, because both will be more or less omnidirectional. JBL also has a new line of Synthesis ceiling speakers with a novel waveguide and driver mounting. Sonance might also have a 3-way with aimable midrange. Alas, no measurements available for any of those, which sketches me out a little. Nobody seems to publish useful data on ceiling speakers.
