THGTTG is very important to me and I consider it (and the subsequent books in the series) to be a masterpiece. I consider Adams a "cynic with a heart of gold (not the infinite improbability drive powered spaceship)".
Regarding the "talking voice" v the "pretty voice" argument, art is art. The argument is akin to "it's not a poem if it doesn't rhyme" and very tired. The delicate beauty of Prokoviev's Romeo and Juliet is not somehow superior to the fierce brutality of Stravinsky's Rite of Spring, although the former is probably more accessible to the casual listener.
In the end, nobody wins a "my favorite band is best" argument.