Well so far we've had no FW tank dribbles. I filled the tank for our first outing in spring 2013 and it remained 'full enough' until drained for winter.....the process which, by the way, at the RV service center, took way too long even using the tekkies pump gizmo.
Even the tekkie got tired of waiting, we ended with these drains open:
1) main low point tank drain;
2) hot water drain plug pulled;
3) bath AND kitchen taps open with RV pump activated;
4) the tekkie pump was attached to #2.
It still was draining after about 30 minutes, but we finally got it done.
I really love driving this unit on the road. It rides better than my pick up and is just as comfy as anything we drive. Plus I can work in a nap or a sandwich....although Old Blister....er, my Sweet Bride.....has yet to give a try at driving herself.