@Dani Ramz
The Digital Nomad Visa (DNV) is very new, hence folks don't have lots of experience with it. But if you qualify for it, I'm sure it's a good option. If you have plenty of savings, then you could also consider the No Lucrativa Visa (NLV), as you need to show 29k euros. If I qualified for both, I'd choose the latter.
Beckham Law was designed to encourage relocation of employees from another country to Spain. Which, by definition, excludes digital nomads who are location-independent, and perhaps don't even have an employer. However, I understand that there have been recent changes to this law to make it more inclusive. So, again, this newness will mean there is more uncertainty and confusion. My guess is the new changes will include most/all digital nomads.
On the passport front, the special Spanish regime for Ibero-Americans is a big draw. My partner (Brazil) went nuts for it when she found out, so even though we were resident elsewhere in EU (Bulgaria), we had to get residence in Spain too. The headline number is 2 years, but I'm not sure how easy that is in practice. We got residence here in early 2019, and my partner has still not received her passport.
My understanding is that this regime applies only to Ibero-American citizens. Your profile says American, so hispanic heritage is unlikely to be sufficient, unless you have dual citizenship in Latin America. Although perhaps specifically Spanish heritage helps. You should also note that, officially, Spain does not allow dual citizenship with USA/Spain (but does for Ibero-America/Spain).
Separately, I think the appeal of an EU passport is overstated, and I've (unsuccessfully) had this conversation with my partner since the day she heard about this possibility. :-) I'm non-EU too (thanks to Brexit) so an EU passport would, of course, be nice to have, but I'm pretty sure I won't bother. That's because the EU is very good from the perspective of social integration and mobility. I already have 5 years in Bulgaria and I now have my PR (Permanent Residence). This is an indefinite status which is rather hard to lose, and allows me (if I desire) to live in Bulgaria for the rest of my life (with no discrimination relative to Bulgarian citizens, except for voting rights). Moreover, while my PR has no formal rights outside Bulgaria, most EU countries make relocation much easier for non-EU folks who already have PR elsewhere in the EU. In addition, the EU has a permit which is separate from a nation's PR, which is the EU Long Term Resident's Residence Permit (also after 5 years, and typically after your local PR). And this card DOES have many aspects of the Freedom of Movement enjoyed by EU passport holders.