I would even consider it an upgrade to using air from a hand/track pump, and car giant Nissan pioneered the use of nitrogen in the 'GT-R' sports car's tyres to aid traction; they considered regular air to be 'too unstable' for the dependence on the cars tyres.
I think the "added stability" is form the dryness of the nitrogen compared to air, when you cool air down the water condenses, so on a really cold day there might be some condensation in the tubes.
But CO2 from cylinders are dry too.
Carbon dioxide molecules under pressure, can just about squeeze through rubber molecules, whereas nitrogen molecules are much larger, so pressure loss is considerably lowered.
CO2 is a much, much bigger molecule than nitrogen, C O and N atoms are all comparably sized, theres 3 in a CO2 moelcule and 2 in an N2 molecule. That's why nitrogen is lighter for a given number of moles. Loseing pressure is due to the thin sidewalls of raceing bike tyres/tubes, air is 78% N2, if tyres weren't porous to it they wouldn't be porous to air, either that or your tyres would end up full of pure nitrogen as everythign else seeped out, which doesnt happen!
Last of all, making up 78% of air (and rising), nitrogen is an almost infinite resource, so why not use it for the billions of bicycles and cars we have on this wretched planet? I believe there is money in this, somebody please make one!
You can get them, you can also get laughing gas (N2O, nitrous oxide) in the same cannisters, mainly because all three are mostly inert and the main use of those tyre inflator cannisters is acutaly in food preperation (N2O is used for make wipped cream), look at the domain registrtion for tyreinflators.co.uk, it's owned by a catering supplies company.
CO2 is cheep as it's an industrial waste product, nitrogen costs a bit more (not much, at the quantities were talking the bottling/transport probably costs 10x, 100x or even 1000s x what the gas does) as it has more uses and has to be extracted from air.
Back of a fag packet calc says a 23mm x 700mm tyre inflated to 100psi would weigh about
11g with CO2
7g with N2
8g with Air