Just keep in mind that unlike metal, wood "moves" as the humidity
changes. Most countertops are either made of a solid material that
doesn't swell with humidity (e.g. granite, corian, etc.) or are
comprised of a surface (i.e. formica, tile, etc.) atop a plywood or
particle board substrate, which are both quite immune to humidity
changes. If you go with butcher block, you'll likely get significant
growth and shrinkage throughout the year.

That's not necessarily a problem, you just need to take it into account
when you affix your countertops to the cupboards. You'll need to use
connectors which allow movement, like what you'd find connecting your
dining room tabletop to its apron and legs.

One nice thing about wood countertops: If you ever get a bad scratch,
dent, burn, or whatever, you can always sand and refinish.

Josh