I've never ran the Pro Radial slicks but I have ran both the M/T ET Street Radials and the same size M/T bias ply on my old Duster, the radials were right at .012 to .018 quicker ET and right at 2.0 MPH faster on a good track with no other changes.
The bad thing was they once they started to would spin they would go way up on the RPM unless I lifted right away, they would not recover unless I lifted some
I drove that car on the street also and I've had the radials start to spin going around a curve at 60 MPH when I step on it a little to pass another car, NOT GOOD
I think I've heard the new Pro Radial are a lot better at the track than the older ET Street Radials were