The last ST170 I saw was NOT HID!!
I use Philips EXTREME(H4), and they are awsome, went to these from 130/90, and they are still twice as bright.
Dip is almost exactly the same as a 6K HID kit in colour/spread, so this will be the same for single filament like H7.
Best £20 or so I have ever spent on bulbs.
tabetha