The Back Widow Pearl is a strong async ball, so it more pop or hockey stick in the backend. The IQTF is a smooth sync ball, more gentle arc.
So you like async balls at 2.50 .60 diff

I wouldn't buy anything yet, understand the purpose of the ones don't like and try them again. Change the surface before plugging.work with your proshop to better unndedstand them before drilling the new 900 Global.
You need to figure out why before you dump more money into it.
Technically know why

I'll second this.  Surface changes are the quickest and cheapest way to change a ball.  Sometimes that is all you need.  But, keep in mind the patterns that the balls are made for too.  I've seen cases where people will use the oiler on a shot not meant for it and they wonder why it won't hook (it burns all the energy up front). 

I'd suggest working with your PSO and having them on the lanes with you.  A lot of times, the PSO can spot what changes are needed during this and can adjust the surface as needed.  In some cases, it may be a layout change and/or having an x-hole punched to increase/decrease flare.  Sometimes, a specific core/cover just doesn't match a bowler's game and that's when you sell the ball or balls off.

At this point, don't drill the new ball just yet.  Wait and see what the adjustments to your other balls do first.  Once you and the PSO determine the issue, it's much less likely that you'll run into this issue again.

BTW, if the PSO doesn't want to watch you bowl on the lanes, find another PSO. The good shops will always make time to meet with their customers to learn their game and then make the best recommendations on their specific game.