performance with column orders

I couldn't track down recent info in the archives, so I figured I'd ask here.

Does the order of columns still have an impact on table speed? Back in
the olden days, it used to be that fixed width columns (integer,
tinyint, etc.) should be the first ("left") columns in the table and
variable width ones should be towards the end ("right"). This allowed
a database to line up the columns better on disk and give you a speed
boost.

So, does Postgres still care about it? And, if so, how much? The posts
I found were from 2 years ago, and indicated that there is a minor
increase, but not a lot. Incidentally, could anyone quantify that in
any fashion?

Thanks,

-Jim....