At Stage 1 (induction kit & 007) my car made 260bhp/299lb-ft, a second run on the same rollers months after but a hot day and it made 250bhp/280lb-ft, these were both when the car was healthy. A Forge TIP was added and I did my first road log on a cold night, this made 207g/s (circa 260bhp) so everything was fine. The car got older, sensors and hoses inevitably perished and I end up with some issues, so although the car had all this new kit on it, it couldn't really do anything as other things were wrong.
I'm comparing my 40/40 jump to the second, hot day, run as it was similar in temps to the Stage 2 (25c & 26c). Give or take a few bhp/lb-ft it has made significant progress and the smile on the mappers face said it all, you know when you have a goodun if it impresses someone who sees the same thing day in and day out. Now I plan to rip out all the old hoses and replace with silicone so it's done for good.
The Forge cooler made a massive difference, I even felt this when the car had issues but I can't compare it to another cooler as I've never tried one. There's a Forge (smaller cooler than mine) on eBay now...