Re: Nitrogen in Tyres
You are defintely still supposed to check your pressures with Nitrogen.
Of course you are less likely to need to top up, but I read a number of industry articles that stated that it was critical that people still check their tyre pressures or use of Nitrogen would actually be dangerous (due to misuse).
Essentially the permeability of the tyre is only one aspect of pressure retention, the physical well being of other aspects of the tyre (valve, tyre wall etc) are also important, not noticing a slow puncture before a long trip could be dangerous causing the tyre to overheat and then blowout.
I'm not a doctor - but I really do recommend braking later