The big unknown here is what kind of wood you currently have and what
condition it is in. There is big difference between top grade, well
installed and maintained cedar siding and something like cheap T-111
that is poorly installed and not maintained. If I had the former, I
would never cover it with vinyl. However, if you have existing wood
that is cheap and in poor condition, then vinyl could be a reasonable
alternative.



And the same is true of vinyl siding. A cheap product, poorly
installed isn't going to look like a premium one. IMO, real quality
wood will always look better. Think about high end custom homes you've
seen. How many of those had vinyl siding? But real wood comes with
the higher initial and maintenance cost. Which is right depends on
what's there now, what style home it is, what similar homes in the area
have, and your budget.