For me, and this is entirely personal, the strength of the double album is that we finally got away from the situation that occurred on the last 3 70s Eagles albums where Glenn sang either one or one and a half songs. He seems to have finally decided that it was time for him to regain his position as being co-lead singer on the band. I don't know what would have happened if he had agreed with Don that it should only have been a single album. I suspect that again, he would have dropped most of his songs and kept Don's. As it is, at least we have these songs on an album because he doesn't seem to want to play most of them live (although he did play a couple in solo shows).