I sing classical music all the time, in a big group which has sung in Carnegie Hall, the Albert Hall, and the Sistine Chapel, among many other places. And I have to say I agree with the opening poster.    I like opera overtures, opera choruses--and very few arias.   And the main reason is the classically trained voices of the soloists--especially the vibrato.

The interesting thing is that my conductor seems to agree with me on this--he is forever telling us to focus and produce only a straight tone--with very few exceptions, one being parts of Carmina Burana, when he wants an "earthy" tone from the altos--and sometimes from the sopranos.

Reason for his wanting a straight tone:   he wants to be able to add "color" as he sees fit.   Also, vibrato--aside from natural vibrato--can make it seem that you are not hitting the exact note immediately.

I have a friend who was recently let go from the group--even though he is a true tenor, and I always thought real tenors in choral groups could write their own tickets, and were invulnerable to the concerns of the rest of us.    But we have re-auditions every year, and he has a wide vibrato, though he is only about 50.    My theory is that that's the reason he is no longer in the group--which is like an extended family--and nobody wants to leave voluntarily--both because of the music and the camaraderie.