I actually studied that Guinness can in college, no chance the cartridge will explode, your beer would freeze way earlier. The widget is filled with Nitrogen. The only downside is you would be drinking Guiness at way to cold of a temp to fully enjoy!
The way I figure, depends where the bindings are located in the bar should dictate the DIN's. This could also lead to higher capacity in said bar, and more interesting drinking games!
Near bar: DIN set around 8, people will be drinking a lot, but still be in control.
On dance floor: DIN at 14, stop moving, you look stupid.
In bathroom: DIN at 0.5, get the hell out of my way!
On top of bar: DIN at 3, these people are fun to watch fall.
On wall: DIN at 10, keep 'em up there
On ceiling: DIN at 16, but have remote control to occasionally release on binding, could be interesting.
No tubes allowed in bar!