As promised in post #33 I have done some comparison tests on a customers Falcon/Benq vs my Xenon/Samsung. I must say I was sceptical about there being any real issues with the game on a Benq machine... how wrong I was. For the record both machines were flashed with the latest Ixtreme firmware and running at 12x speed. Both consoles had my hard drive attached and were using the same profile.
Both the original and verb backup work flawlessly on my machine, with very minimal popup/texture issues. Load times are swift and never seem to drag.
First I tried the backup in the customers machine, the first thing I noticed is that the game took twice as long to load up. When loading, GTA artwork is shown, my console rarely goes past the third picture before loading my mission, however, the Benq got about seven or eight pics in before starting to load the mission. It was nice to see these new pics but not so good on a technical stand point. The next thing I noticed was the popup... when driving at normal speed I found myself hitting invisible objects that would appear two seconds later (very annoying) Also, buildings would appear as grey blocks and seem to take a long time before the detail was drawn in. Basically it was a popup fest and not a good experience.
Next I tried the original, to be honest I was expecting it to be the same as the backup... wrong again. The original behaved much better and loaded nearly as quickly as in my console. There were still more popup issues than with my machine but they were much less noticable.
All in all I only played about 5 mins on each disc but it was long enough to see a difference.
Basically, if you have a Benq drive, run your original disc or buy another drive.
Never thought I'd be so happy to have a crappy old xenon with a sammy drive

EDIT... Took some load times if anyone's interested. I timed from the first screen with white writing on a black background to seeing Niko in his apartment.
Benq orig - 1:09
Benq backup - 2:04
Sammy orig - 1:12
Sammy backup - 1:11