Moving every few months was a great way to explore a variety of cities that we wanted to check out, but we decided that staying within Schengen for more than 90 days would allow for us to be nomadic in a more leisurely way. Additionally, it would enable us to have an easier time undertaking some things that are facilitated when you have resident status, such as participating in the city bike rental system in Spain, or opening up a bank account. Ultimately, we want to continue traveling, but to have a bit more of a 'home base', where we are able to keep the few things that we own, and can stay indefinitely without needing to worry about overstaying a visa.
We ended up applying for the Spanish non-lucrative stay visa. This visa, issued for a time period of up to a year, and renewable upon its expiry, allows us to live in Spain as long as we don't work while in Spain. Since Jones works for a US employer, and my clients are outside of Spain, it seemed like a great fit. Unfortunately, this necessitated a trip back to the US from Edinburgh, as we didn't have permanent residency in the UK, and thus weren't able to apply through the Spanish consulate there. Moving back to the US was complicated by the higher cost of living compared to the cities we'd been living in, as well as the difficulty in finding long-term housing.

Nomad Hound is pleased about our return to Spain. Lots of exciting things to sniff, we hear.
Since finding out that we got the visa, we have been making arrangements to move back to Barcelona in a few months. It's been fairly straightforward this time, as our past couple of trips have familiarized us with the city. We have a better idea of where we want to live, a short-term apartment company we've worked with before, and Nomad Hound has his EU passport all ready to go. We'll hear back about our apartment hunting plans and finalize travel dates in the next week or so, and write up some posts about the moving and visa process for other Nomads out there hoping to do something similar.