I haven't had a Wald basket on a bike since I was in college, but I have one sitting out in the weather now (actually it has been out in the weather for about a year when I removed from a bike I donated) and I suspect that it spent many years outside before that. There is no rust on it, so the galvanizing must be decent. What I dislike about it is that the struts mount to the axle and the inverted J-clips that mount to the bars.
I agree that the wire is under-sized, and the basket deforms more easily than it should. All in all they do work. I wish Wald would make a higher quality basket as an upgrade product.