I've always been a fan of Du Pre, particularly her huge, husky sound (which I think is spectacularly showcased on the Brahms pieces).
I will admit that the Franck sounds a bit labored at times (compared to, say, the much leaner rendition by Muller-Schott, among others), but I can't help but be moved by this recording. Knowing this was recorded near the end of her career, I always think about the mixture of sadness (at losing her ability to play, among other things) and joy (at still being able to share this musical moment with her husband, who is her pianist) she must have felt. I love the Franck, especially the last movement, which seems to express a similar mixture of sadness, longing, and outright joy. I can't imagine a better vessel for expressing what she must have been feeling at that particular time.
I'm normally one to judge a piece purely on the end product (without considering the circumstances under which it was played or recorded), but something about this recording just touches me. To paraphrase Alec Baldwin from 30 Rock, if you have "two ears and a heart", this recording is a must hear.