I've had 2 IQ Tour Solids - one pin down, and one pin up. I still have the pin up one.
I had some success with the pin down one - winning a USBC Masters qualifier with it. However, other than that, nothing. I could never really get the ball to transition from hook to roll quick enough to feel comfortable with it on almost all conditions - most of the time it would just plaque when it would get to the pocket. The pin-up, with the quicker response layout, has been much more versatile for me. While it's been better, there are better options for my style of bowling on most of the conditions that I encounter on the left side.
Ultimately, what I have learned from the IQ Tour Solid (and the Gold Ball/IQ Nano/UpRoar) is that low diff balls seem to be condition specific for me. They work best for me when the back ends are SCREAMING. These balls don't peel off the spot for me, so there is a place for them, just not that often.
I also have two. Both are 5x40, with one of them having no hole and the other having a big hole down VAL. Pin downs almost always give me the same issue you saw with yours, so I decided not to try to separate the two that way.
End result: the motion I get out of each is absolutely perfect on house shots. The no hole is my go-to, with the hole down version making appearances on longer house shots or carry down. As I mentioned before, I've been able to play every house shot in my area with just IQ, IQ, and mix. That includes multiple tournament cashes and a couple 800s. The motion is perfect, I just need to pick where I want it to start up on the lane.