The first three I didn't really regard as having singers, just people shouting or squealing (the Dane), besides that much of their music was just too fast for me, I can't find a beat with that ultra-speedy stuff which would become a determining factor of much of Heavy Metal from the 80ies onwards.
Queensryche I liked, it was very artful and tidy. Empire was brilliant, very refined songwriting, I prefer(red) it to Operation Mindcrime.
Back then and today, when faced with the choice between speed, thrash and death metal and quirky to pop'ish New Wave, I always go for the latter.