I would personally go for the K1 versus the CR1 given the turnaround times are a big difference and with the huge backlog of petitions in the USA it is known that the K1 Visas tend to move faster versus the CR1. It was still the same back when we did all of that. But as someone else stated either way it is not a fast process unfortunately and depending on the service center in the USA and such you're assigned to and vice versa it just depends. I think you need to do what you both find to make you the happiest. Would it make you happier marrying in Finland or in the USA and such which is the most important thing in my opinion!