Not watched the video yet, but I can tell you I've done 115 (GPS) through craners, in a sheddy old BMW. I'd be disappointed at only going 1mph faster in a GT3RS.
If you were going that fast through craners, you should have been blitzing pass me as I only sit at approx 100-104mph through craners and 108mph being my fastest through there. I do play it safe through there on purpose though as if it goes wrong there, its very messy.

In the CSL on PS2's I was quite happy to go through there at 110-112mph, it just felt safe and happy to do so, in the 911 Craners seems to really amplify that anchor out back.