I actually stayed in 'El Centro' when I was in Medellin - for those who are not aware, it's the area with street girls, drug-sellers, homeless etc and it's meant to be very raw. Just search for the YouTube vids to get an idea. When the taxi guy dropped me off, he kept asking in Spanish "Are you SURE you're staying in El Centro and not in Poblado? I kept answering 'Yes, I'm sure'. And then when he dropped me off, he waiting on the road, to make sure that I got into my hotel (a distance of 20 feet from his car to the hotel entrance) and I gave him a thumbs up as I walked in, and he returned the thumbs up with a smile.
I stayed there for almost a month, and nothing bad happened to me. I guess I was lucky. I'm NOT implying that Medelling is safe, or that El Centro is safe. It can be a lottery. One night me and Polish guy I met my hotel (I met him in the hotel lift and during polite conversation, he asked "What are you in Medelling for?" and I replied "For the pussy". We both burst out laughing and then went punting together from that point. Sometimes, you just have to be direct.)....so me and this Polish guy went to the local pussy bars in El Centro at 11pm where the only foreigners were me and him, and I was sure that this is the night we'd get mugged. But nope, the universe looked after us. There's a whole bunch of these bars on Carrera 53 near Avenida de Greiff, if anyone is feeling up for a challenge.
Take precautions, go easy on the alcohol, and there's tons of Paisa pussy willing and waiting to be pumped.