For the sake of "if it isn't broke, don't fix it", it takes roughly between 30-60 seconds to go from the Data Installation prompt (if you did do the installation, then start at the Seizure Warning screen) to the main menu, possibly longer, but no longer than 5 minutes.
I find that it's taking way longer if connected to internet then without... Though it doesn't take longer then max 3 mins tops even when connected to internet on my PS3...
2 mins is the normal data loading time.
Theres a 8 second delay in hitting x in the video as I dropped my coca cola bottle.
(time line is not edited only editing was conversion and crop)
Maybe it could be a large save file? And deleting GT5 data (the core data that's installed when the game prompts you whilst boot-up) could free up some seconds, but that's not a guarantee. Patches, HDD space, replays, etc. could also raise the loading times a bit.
I think am hovering around a full minute, maybe longer. I have about 5.5MB file and have all patches and installed the stuff from the disc. I am running a 20GB model with a 5400RPM 160GB drive.
