Driveshaft is out and goes in for work tomorrow. After its back in I'm going to pull the front and grease it. I was amazed at how much easier and more complete it was to pump out the old grease on the workbench. (I'm only replacing the rearmost U-joint so I cleaned and lubed the other)
Driving on FWD was fine, handled mostly the same, but was smoother, so I'm sure to be getting some vibration from the rear driveshaft. Makes sense with a loose u-joint.