I use extended choke tubes on all of my shotguns...but I don't think there is a performance enhancement. Most of the big name companies make good chokes....but Briley is probably the leader in terms of quality.
They're a little easier to tell what chokes you have in the gun...but if you know the marks on the flush chokes, they're pretty easy to see as well.
They're a little easier to change on a sporting clays course or in the field.../ but flush chokes are easy to change as well without a wrench. In my opinion, chokes should only go in "finger tight" ...and they should spin in and out easily with just finger pressure ...for flush ones, just stick your finger inside them and spin them out. If you need a wrench to loosen them, you cranked them in there too tight, in my opinion.
I like ported barrels ( helps reduce muzzle rise between 1st and 2nd shots, in my opinion ) ....but I don't know about ported chokes...