They look nice. How do they fit?
[snip] the spheres are meant to be used further back in the room.
The spheres help from further back by increasing on-axis sensitivity in the upper presence range versus the off-axis response, and are appropriate anywhere that attribute is desirable. It's more about that on-axis/off-axis difference than the difference in overall integrated frequency response, which can useful but can be EQ compensated for just like compensating MK3 response to that of MK2 or vice versa. The on/axis off/axis difference cannot be EQ compensated for afterwards.
Consider that the original Neumann M50 (and later models) upon which all these spherical attachments are descendants is primarily used for main microphones positioned over the orchestra conductor's head- a position not significantly more distant than a stage-lip taper position in some cases. The acoustic situation is different however, with an unamplified band (orchestra) in a large hall and good sounding, relatively long-decay reverberation time.
With all that in mind, the main difference you are likely to hear with and without the spheres
after optimally adjusting EQ of both for good direct-sound from the band, is the difference in timbre of those sound components which are not arriving directly on-axis - the room reverberation, audience reaction, and perhaps off-axis PA bleed.