Interesting discussion--after 12 years on the road, the front bags on our 03 are starting to leak [coach settles after a day or two]. I tend to agree with Dave--suspect the leak is in the "plumbing" [eg dump valve or connection] vs the bags themselves. I am told the bags are good for millions of driving miles but like tires, age could eventually be a factor. Think I will let them go for awhile before considering replacement--in the interim--I may try searching for the leak but right now the leak is so slow that it may be difficult to find.....
2003 40' MDTS
Garden Ridge, Texas