. . . . oops . . . so do I.
That English sound, you know . . . :-D
We did the Saint-Saens "Ave Maria" two Sundays ago and the Fearless Leader did permit vibrato in that one, within reason (that is to say barely audible). The rest of the time, he glowers and holds his index finger up sideways like he's going to shoot somebody . . .
But, seriously, when you have a choir that's composed of non-professionals other than staff singers (like ours), a straight tone really is better overall. Otherwise some folks (they're over in the soprano section mostly) get completely out of hand and are fluctuating a half tone or more either side of the pitch and never get back to dead center . . . . ;-) (OUR section's problem of course is that we roar in the fortissimo passages when we get to use our middle and low registers . . . choirmaster rolls his eyes around and muses, "hmmmm, fog rolling in.")
But our music is excellent. The Fearless Leader really is a genius for selecting text-appropriate anthems with good (but difficult) settings, and he digs up remarkable music both old and new. (I can mostly leave the new stuff, but that's just me.)
There are those, of course, who have a wildly fluctuating vibrato which has to do with gross ignorance OR (in most cases,) flaccid vocal cords--either from superannuation or simply not enough singing.
Having said that, there are two distinct schools. The English like the straight tone, and the others (Roger Wagner, Bob Shaw) prefer the well-disciplined vibrato.
They both work.