The tuftex 24 due to its mould shape is not as strong as the Qualatex 24, this is due to neck diameter and the angle from neck to body of the balloon being tighter increasing the force on the inverse curve to the neck meaning they are more dangerous to neck (albeit quite exciting :3 ) Proving the above with a high speed camera and a very accurate pressure guage was cool too!)

This one got to about 27" and was rock solid with the neck pushed out, it survived a long time and lots of play, at the end of its life it didn't pop, it was deflated (if something has done me a good service, i'm not going to destroy it for the sake of it)
The photo is quite deceptive due to background and being taken with a phone camera, my handspan is 11" so the neck is quite wide, its just dwarfed by my shovel like hands ^.^