The H9 indeed contains more or less the same exact algorithms as the 'factor series boxes (and then a few more, besides), but if you’re only really looking for pitch shifting, a used Pitchfactor is a better idea since it has hands-on control of every knob whereas the H9 requires you to use an app or click a few buttons to access all the parameters from it’s single knob.
As for their algorithms, they’re beautiful on vocals, instruments, basically anything that’s monophonic. There are a handful of situations in which the algorithm works “okish” with polyphonic sources but in general as long as it’s monophonic, it’ll track and shift and shimmer and glisten and tune and tweak to your heart’s content. As @junklight said, Eventide is the gold standard for portable pitch effects.
If you want to go one notch higher, the Eventide H3000 and Eclipse v4 are rackmountable hardware units that go far beyond the stompboxes in terms of flexibility and algorithm design, allowing much more customization and flexibility, but of course they are larger and costlier.
All Eventide gear is extensively MIDIable in realtime for even further pedalboard interaction or DAW integration, too.