For the record I said careless not stupid
Perhaps some who have owned standard glass tanks for many years have grown accustom to a more aggressive cleaning technique which perhaps is too much for starphire glass. However with a little care, which you should apply regardless of what type of glass you use, will insure your starphire tank never gets scratched. I've pretty much always had starphire tanks, never had an issue and I use standard cleaning magnets for glass, not acrylic or anything special.
In regards to different types of low iron, I had a theory not long ago regarding generic low iron to be easier to scratch than brand name starphire. This was due to the discovery of a scratch after cleaning my new tank for the first time which has generic low iron. However after talking with people involved in building it and a few tests it's become fairly conclusive the scratch was there before I filled the tank.
At the end of the day, glass can be scratched, how easily really depends. The bottom line is if you're not the type of person to take a little extra time in ensuring you're not doing something that potentially scratch your tank then you shouldn't waste your money on a more expensive version of it.