Thought I'd resurrect this thread once again. I finally gave in...and replaced the battery in my MBA again. This was the 3rd change, and about 3 years since the last time.
I think I had a faulty battery for the first change, it only lasted about a year. The second lasted 3 years. It was still functional, but I'd get maybe 2 hours of life out of my computer when fully charged. Since replacing it earlier today, after an hour of usage, the battery was down to 87%.
Every now and then I see that Costco has MacBooks on sale and I'm tempted...but this machine hangs on.