My dad had one on his GTP that he put on with his 3.4 pulley and TEP CAI when he bought the car. (they were the only 3 mods he had until it had ~15k on it) It worked nicely. The tranny shifted harder and quicker, and if you want to beat on it and smoke the tires on the 1-2 shift you just crank it up all the way, and when you're done having fun, turn the **** back down and drive it normal again. Its not a direct replacement for a shift kit, but it works good, and if you don't want to drop your tranny pan for whatever reason, you don't have to. The setting my dad had his set on for his daily driving shifting significantly harder than his TEP shift kit on medium w/DHP with increased line pressure.
The nice thing about it is ease of installation, it literally takes about 2 minutes to install. Then when you need to get warranty work done (assuming the car is under warranty still) you just unplug it and bring it in. Then when you get the car back, plug it in again and it'll be right back to shifting firm again.
1990 Maroon Grand Prix STE McLaren 3.1 Intercooled Turbo, 14.695 @ 94.49 on 12psi before cam/heads/etc.
1990 Bright Red Grand Prix McLaren 3.1 Intercooled Turbo, 14.819 @ 92.72, 189whp
1999 Grand Prix GT 9.75:1|K&N|160 tstat|No Ubend/Cat/Res|UD Pulleys|Ported M90/TB/Heads|XPZ|2.55"|Pacesetters|Stage 2 I/C. 12.442 @ 112.78
2000 Blue Bonneville SSEi Supercharged Gutted Airbox|K&N|3.4"|1.9'*|WP Pulley|Custom DHP|180*stat|41932'*|No Cat. 14.681 @ 94.80
2002 Dark Cherry Grand Prix GTP Supercharged & Intercooled
12.084 @ 114.38 w/1.743 60', 315.6whp, Fastest Stock Cam M90 GTP!
NOW XP CAMMED, 340.6whp with XP, stock heads, Gen 3 M90, 11.984 @ 115.84 w/1.750 60'!
Most HP Stock Heads Gen 3 M90 GTP!
2004 Red Monte SS Supercharged K&N|3.4 Pulley|1.9'*|180*stat|41919 plugs|3" dp|No cat/ubend|DHP|Shift Kit. 14.2 @ 98
GOT BOOST??? Friends dont let friends drive stock!