We have had a Spyder 320 for over 3 years now. I haven't seen the HP in action so I really can't compare. All I can say is the 320V speed is in between the 320 and the Turbo. I believe the head array is different on the 320V as well. Similar to the Turbo. One thing you may want to keep in mind is printing pastels. On our Turbo, it's hard to cover any type of smears or fingerprints when printing pastels/light colors because of the head array. For some reason the Spyder 320 (not the V) has the heads lined up in a row, which seems to cover fingerprints,etc. a little better. The head arrays on the Turbo/320V are staggered
I don't know why the head arrays make a difference but they do.
Please keep this into consideration.