For my own part, I'm reading John Woods', and I can tell you exactly why. I read the Porter translation of Doctor Faustus and found it decent, until a few months later when I happened to get a hold of a copy of Woods'. The Woods was clearly superior work, so I saw no reason to even bother with the Porter for Buddenbrooks.
According to Theodore Ziolkowski's review in The New York Times, I made the right choice:
These inadequacies alone would probably justify a new translation. John E. Woods, whose intrepidity in the face of linguistic difficulties is attested by his prize-winning renditions of such writers as Arno Schmidt ("Evening Edged in Gold") and Patrick Suskind ("Perfume"), is not dismayed by Mann's play with dialects. He has restored passages omitted by Lowe-Porter and found ingenious renderings for tricky puns: for example, a Latin teacher's rule of thumb for rules of gender: "What's good for the goose is good for the gender." He has also retrieved occasional passages that Lowe-Porter omitted for reasons of delicacy: some lines on flatulence, for instance, that aptly characterize Tony Buddenbrook's boorish son-in-law.
Elsewhere Mr. Woods's vocabulary is closer to the earthiness of Mann's language, as when Hanno Buddenbrook, after gorging himself on Christmas sweets, states that he's about to "throw up" — which Lowe-Porter ambiguously renders as, "I think I'll just have to give it all up." Mr. Woods not only remains closer in vocabulary to Mann; he renders Mann's style more faithfully than his predecessor, who did not hesitate to recast and shorten Mann's sentences.
It is a truism that every generation needs its own translations. Lowe-Porter provided a valuable service by making Mann's novel initially accessible to the English and American publics. In Mr. Woods's sparkling new translation, the reader approaching "Buddenbrooks" in English now encounters a work that is closer in style, vocabulary, idiom and tone to the original and can thus appreciate more fully the monumental achievement of the artist as a young Mann.