I have both VR Solid and the IQ.  Not the IQ Tour.  As far as the IQ vs VR Solid go, I see about a 2 - 3 board difference at the arrows with similar layouts depending on lane conditions.  Keep in mind that the cores are different and give you a little different reaction shape on the lane.  The Centripetal core in the IQ is low RG and starts up on the lane sooner than the Inverted Fe3 core in the VR Solid.  The VR Solid will give you just as much backend due to the nature of the R2S cover but the IQ will allow you to play in more oil due to the more aggressive cover and core.  Bottom line, the IQ is stronger overall and the VR Solid is a step down.

As for the IQ Tour, with that ball you are going to see a control type reaction throughout the heads and midlane with an arc shaped entry into the pins.  No hockey stick shape here...but it does recover nicely.