I've lived and worked in both Spain and Sweden in both Winter and Summer, and hands down I prefer Sweden. I love both seasons in Sweden, and hate the Summer in Spain.
There's every chance I have a better personal cultural fit with the Swedes, but that's very much a personal thing. In my experience English is more widely spoken in Sweden than in Spain, which also makes it easier for me. I think the economy in Sweden is stronger.
Mostly Valencia, with some time in Tarragona, Palma, and Cartagena. Mostly I was working there, but I knew I'd be there for some time, so I integrated as quickly as possible.