buzylady: Yeah they probably dry out a bit quicker than a plastic hanging basket.
As far as the water running out too fast, you may need to make your moss layer thicker. They say to soak the moss and squeeze it out before lining the basket, and make sure that the moss is thick enough and densely packed all the way up to the top of the basket to where you can't see any of the wire at all.
The adding a baggy to the inside to line it may help, but probably depends on the
plants you want to put in it since the water would then not drain out much and might cause some waterlogging, especially in wet weather. I haven't tried it though.
rucrazy: I grew up in Reading, about 50 miles west of London, and then lived in Cambridge for a few years before I moved here in 1992 with my USAF hubby :-)