As DSatz mentions, height information isn't the most useful aspect of ambisonic recording for most users. From my experience using the Tetramic, I find that generally true for recordings made from relatively distant positions. However, I've found the ability to 'tilt' the virtual microphones either up or down after the recording has been made valuable when recording from on stage, as doing so allows for a very useful way of tuning of the sound balance. It can also be useful out in the audience and somewhat close to the stage if significant sound reaching the recording position is emanating from both the instruments and amps on stage as well as from a high flown PA.
For example, onstage with a jazz combo and the mic 4'-10' or out in front from the drum kit, one can tilt up for more cymbals and down for more kick. One can also tune the timbre of on stage elements by pointing up or down to catch more or less of the floor reflection, and the tone and presence of guitar amps can be tweaked that way. I've also used the vertical height tweak to help bring out on-stage instruments that have low on stage levels, one time dialing in height adjustment to point at a rather quiet muted bass-trumpet to maximize pickup of what sound I could get directly from it. Those vertical angle tweaks can be done without changing or compromising the desired microphone angles in the horizontal plane, so stereo imaging needn't be compromised as a tradeoff. Sometimes by dialing in by ear what sounds best, I've ended up with situations like the left virtual mic pointing down say 10 degree and the right one pointing upwards at 20 degrees or whatever, while retaining a more or less standard coincident stereo horizontal angle of 110-120 degrees between virtual supercards. That's valuable flexibility.
Yet in the horizontal plane a Double-Mid/Side arrangement using with standard capsules is capable of achieving performance similar to a dedicated ambisonic microphone, and has the advantage that the mics can be used in other non-dedicated setups.
- And of course this kind of freedom provided by Double M/S and ambisonics comes hand in hand with the burden of having to use these tools to dial in the appropriate 2-channel stereo output. It's fun to play around with, and the results can be great, but it can also be difficult to settle on a decision and doing this kind of post recording work is more than many tapers will care for.