Bert Hyman wrote:

We currently have turbine-style vents which were installed decades ago
when the attic was insulated and vented.

The turbines have moving parts and I'm certain that they'll start to
fail soon, probably at the worst time. Last winter during a nasty cold
spell following a heavy snow, one did start screaming as it turned,
but quieted down as soon as the sun came out the next day. We
probably won't be so lucky next time.

On the other hand, the turbines are tall and stick out above the snow
on the roof. We often have a foot of snow on the roof for months at a
time.

Other than trying to avoid turbines, does the style matter, so long as
they're big enough and there's enough of them?

I'm a fan of turbine vents, especially where the summers are very hot.
They work better than passive vents, and are straightforward to replace
if they get noisy and/or rusty.