Just spent 5 days in Cali, and the comparison between the two cities helped my structure my thoughts about Medellin.
Medellin, in the popular areas, is nowhere near as friendly as Cali. But, when you move out to the places that do not have 50 hostels, and gringo gulch, it becomes more friendly. The weather and landscape of Medellin is beautiful and fresh. Cali has some great malls, and areas that are on par with the nice locations in Medellin, but they are smaller. the number of sophisticated / educated people are less in Cali too.
There are some pretty girls in Cali - absolutely. But, nowhere near the % of VERY attractive women in Medellin.
I feel a little safer in Cali. The tough guys are much more open and tolerant of visitors here. In Medellin, it is best to keep a lower profile and not mix. This is a violent country, and [snip] happens all the time ... it is best to at least know when you are taking risks, and at other times hedge against it.
It is hard not to love Cali. It has a great vibe. The place is amazing for the ego. It is fun and exciting. But, Medellin still seems to be two notches above to me.
Meeting women gets easier and easier for me as my language skills