Wilderness Systems Pamlico 145T -- to rudder or not to rud..

I am looking at the Pamlico 145T tandem kayak, which has an optional
rudder. If you have some experience with this boat, (or the slightly
longer 160T) please share your thoughts on the worth of adding the
rudder. The boat will be used very occasionally on class 1 to 2
rivers where the rudder would by locked up and out of the way. The
vast majority of usage would be on flatwater lakes and bayous. If you
don't have the rudder, do you wish you did? If you have it and have
played around with using it and not using it, does it make a big
difference in tracking? Thanks. Burton