At this point in the history of performance style, you only have to say "period instruments" and people know where they stand.The audience that might love a HIP Bruckner fifth will head for the entrance; those who despise the idea will head for the exists. There's a bit more to say here, however. Philippe Herreweghe is a musician of stature, and his Champs-Elysee musicians have on the whole overcome the irritants of wheezy woodwinds, scrappy brass, zingy violins, and bad intonation, the endemic curses of early music bands in the past. It is plausible, if you tolerate a period approach to Romantic music, that Bruckner won't be destroyed after running him through the HIP mill.
In fact, this is a serious interpretation. Nobody was saying, "Oh boy, let's make Bruckner sound like Vivaldi." The absence of vibrato will never be a plus for me. If I were to judge this Fifth by the undernourished string sound at the beginning, noting else would have mattered. But Herreweghe is highly expressive, and one has only to hear the beautifully phrased Adagio to feel impressed. Ultimately, the Bruckner fifth rises or falls based upon how well the conductor can hold it together and deliver a satisfying whole out of the work's disjointed, rambling parts. They are inspired parts in many ways, but the symphony' stop-go pacing and frequent interludes of slow chorales are an obstacle for the listener. It's hard to tell a coherent story form beginning to end.
Herreweghe does as well as most. His earlier Bruckner recordings felt a bit pointless to me, a bundle of HIP gestures without overall meaning. But the fifth has so few outstanding recordings that there was room for improvement. Herreweghe's two big successes are the adagio, as mentioned, and the problematic finale. It is such an omnium gatherum that nobody beyond Furtwangler makes it sound coherence -- and he succeeds only through magisterial force of will. Herreweghe cuts the Gordian knot and lays the movement as a sequence of episodes, each with its own charm, sometimes punchy, sometimes spicy, sometimes solemn and noble. Far better that than straining for grandness but achieving only grandiosity.
The other two movements fare less well. The choppy Scherzo sounds impatient. The first movement, which resounds with theological implications, fails to find a sacred center or spiritual depth. For some listeners, those who want their Bruckner taken out of the cathedral, this lack may be a plus. I've heard the Clevelanders under Welser-Most deliver an equally dispassionate first movement. there, as here, it's refreshing for ten minutes but aimless thereafter. In any event, there's much to admire here, and except for a very few minutes, the imposition of period tics was no bother at all.