I'm allright with the things we have currently, pretty much got used to it. About über-heights and immersion, if tend to react on heights mentioned in the description and a towering figures can be really demoralizing....neck hurts always looking up
Not to mention falling in love to every super-model character....so yes actually these petty things have some effect on some of us roleplay....at least it has on mine. (side note: I usually just ignore unrealistic unhuman descriptions, like the unmatching eye colors, and 7' height or the beauty matched to a godess'.)
What might be able to solve the problems though and add to immersion, if we could use the human race with other races' models. So a half-orc model, human race, for a bulky man...just give him some normal human head, or a dwarf model if you really want to play a midget who's not a dwarf.
Extremities like such, would likely throw the character into the caliban faction. (Question: a 7 feet tall human is considered a caliban no? As it's just unnaturally huge!! )