I like rectangles but most "digital" layout folks
like paths, they are easier to manipulate (stretch)
later. They can be prone to off-grid corners if you
set the width and justify properties wrong, and
the endpoint is often a nuisance (end up with
weird notches / stubs etc. if you don't double-
click just right).
If you're doing a lot of long and non-straight
routes, paths are probably your friend. I do a
lot of analog / power type designs where I care
about trace geometry and often taper it, which
a path can't do but merged polygons, will.
They all end up the same metal in the end, pick
what suits your layout style.