vocal range

goodness. I have been awfully busy this past week, and this next promises to be no different.
I was thinking, as I was warming up my choir this morning, more about vocal ranges and why it's hard to find songs that no one complains about.
Certainly, it is extremely rare to hear people complain that a song is too low. Usually, people just sing quieter if it's truley too low, instead of where they end up screeching or straining their voices when it's too high.
The psalm I used today went down to a Bb for the refrain, and I could certainly tell my cantor at the first Mass was straining. I promised her I would bring it up next time. (But how much? It goes up to an Eb at the current level, and I'm trying to avoid using the key of C right now b/c I had to take out an important C pipe because it was ciphering-I suspect because of the dryness. So that leaves me with B or Db-the most beautiful of keys, which in itself is a big plus, but that would mean it goes up to an F#/Gb. We'll see.)
ANYHOW.
I was thinking as I was warming up my choir that it's not just that men's voices are in general a step or so higher (minus of course an octave) than women's, but that perhaps between different men (tenors vs. basses) there is a greater range of uncomfortableness than between sopranos and altos.
Like, sopranos and altos seem to be all right between a low B and a high C# (some of my older altos will start complaing around then,) on the other hand, my tenor (singular...) is fine up to an E, but I noticed as I was working with one of my music school tenor friends, he said that he can't even sing a low C loudly. Maybe that's why there's so many songs inthe key of D. (which I then complain about cuz I really don't like hearing women sing a high D!) But in contrast to all of that, the basses love getting all the way down to a G or F, but they complain when songs hang around high C and D. So basically, it's the tenors that mess everything up...
Ah. I really ought to do a study on this with different people, both trained and untrained singers, and record their comfortable vocal ranges.
But of course, a song that is comfortably high at the 430p Mass will be ridiculous at 8am the next morning! Ah, another reason I need to vastly improve my visual transposition skills...