The question is not specific to Nano for sure, but since we seems to have the best tech for p2p transfers and the best community - I'm interested to know what the community think about the subject.
Assuming that average Joe already have some nano and started using it on a daily basis he'll need to include every single of such transactions in the annual tax report in most of the countries today. So even if he was that lucky and spend all his nano for the same $ equivalent that he acquired it early (not gonna happen, but the question is not about gains and loses of money because of it) - he still need to do this routine of collecting/remembering/tracking of his expenses for the report during a year. This particular formality to me seems as a huge obstacle on the way to adoption not to mention the fact that you have to expose all your personal spending habits in a very centralized and organized way just to justify that you do not own (or have paid enough) taxes.
PS. Lets do not go into "you don't have to report some/all transactions" as if you plan to spend your crypto on something substantial in the future (assuming it will not go to 0 in value) - you'll have to report the source of the income to justify the corresponding expenses if (or most likely "when") asked.