I think the Holley would could help drivability. I know my car idles and drives better than it ever did with a tweecer or megasquirt. Hard to quantify the value of drivability but if it allows you to enjoy and drive the car more than the current setup then maybe the $1600 price tag is worth it. You can always sell of your current setup to recover a few hundred.
1989 LX 5.0 - 333 Mexican block, Eagle 4340 neutral3.25" crank, Probe SRS 9cc dome .040 psitons AFR 185 Comp heads, FTI HR cam 239/244 613/613, Edelbrock Victor 5.0, 90mm TB, BBK 1 3/4, C4 and 4500 Circle D converter, 4.10 gears
2012 GT/CS 5.0 - Yellow Blaze Tri-Coat metalic, A6, HID.