Hello TheMasterOfGoingFaster,
EXTRA TEXTURE is a fine album, I like it very much. But you have to be as crazy as I am, if you say the same after listening to the album, 'cause there are only three real fine tracks on it : YOU (It was George's single in 1975), THIS GUITAR (CAN'T KEEP FROM CRYING) and TIRED OF MIDNIGHT BLUE !!! Specially the last two are my favorites. The rest of the album is filled with boring songs, not really remarkable.
DARK HORSE is another typical Harrison-Album : Only a few good songs on it, the rest is ok, but not smashing Rock'n Roll stuff. If you listen to George's voice, you can hear, that he wasn't in a good mental condition (I think Patti changed to Eric in those days, there is the song BYE BYE LOVE on DARK HORSE too).
I love that album, although it's not one of Harrison's best, because it was my first Harrison album I bought, exactly when it was released, in 1974. I was 13 years old, a huge BEATLES fan, and then a new album from GEORGE, wow, it's nice to remember.
So buy them both, you'll get some fine songs of George !!!