your observations don't surprise me at all...soundstaging is a delicate thing. i've seen dramatic changes in depth, height and width by changes various components, especially amps and preamps.
as for what gives a sounstage height, i'm no expert but i suppose it's just very low-level detail, e.g. reflections off the recording studio floor and ceiling?
as for what gives a sounstage height, i'm no expert but i suppose it's just very low-level detail, e.g. reflections off the recording studio floor and ceiling?