My ex and I went for a K1 over a CR1 because it was important to me to have him here as soon as possible because I missed him so much, and at the time (2010) the K1 was being processed a lot faster than the CR1. He wanted to do the CR1 because he said the process of AOS was going to take too much time, and he wanted to make sure he could keep working (he had a business back in the UK that was seeking to expand over here). Even though we went through AOS very quickly (maybe just under 5 months? it was a long time ago), he was still pretty frustrated and wished he'd put his foot down and insisted on a CR1. It caused some early friction in our marriage, but for me, a K1 made sense at the time. I might think differently now, if only to have spared him the frustration during that time.
It's a personal decision for each couple, I think. If your spouse-to-be is likely to feel upset at feeling like their life is on hold, a CR1 makes more sense.