"Then Play On" was a disappointment to me -- at first. I was very familiar with the albums of the earlier years, and loved them. I still do. But that particular album really grew on me, and made me wonder where they could have taken the music. It might even be my favorite album from that incarnation of the band.
Sad to say, I'm not familiar with Bare Trees. I'm acquainting myself with it now, however, and so far I dig it.
Wore out the Bare Trees record in college. Literally - had to buy another copy. I still love that Bob Welch - Danny Kirwan era Mac. Of course Greenie's tremendous guitar playing wasn't there, but with him gone, the rest of the band really developed their songwriting. They had much better - albeit different sounding - songs when they had McVie, Welch, and Kirwan all writing.