I've been prescribed Adderall for over half of my 20 years and 5 of those I've been abusing it on and off, and of all the ROA's (ive tried em' all except I.V.) I would by far say oral is the most efficient. you get alot more euphoric, and it lasts much longer. (though I myself don't find Adderall so euphoric, just mildly) and I find snorting to be a waste, because there's just so much f***ing powder you have to put up your nose, it just ends up turning into a nasty bunch of sugary runny snot that doesn't absorb or do anything but sit in/drip out of your nose until you blow it out... only way snorted addy works is if you have the tolerance of a toddler and just need like a quarter of a pill to get high, or if your just snorting a bit of a booster like a quarter or half of a pill.
otherwise its a waste IMO. just pop that shit and chew it up. and to sort of answer the OP's question, yeh I find most of the generic Adderall does burn. not sure what lab my generics have come from in the past, but most of the times ive had different generics they all have been bitter when I snorted them. and don't even bother trying to snort the xr version.