I don't personally know much about Medellin, but know a couple of guys who travel there quite a bit. Don't have much to comment on the city itself, but I have heard many of the positive things written here echoed by my buddies.
On Spanish, if that is a (I know, not the only one) primary motivation, I'd have to vote for Colombia.
Nothing at all against the Porteño accent, but from pure ability to be understood, learning a new language, you'd be far better off learning a more common Spanish first. I first learned Spanish some 30+ years ago in Texas, first in high school then working alongside Latino laborers (mostly Mexican, but many Central Americans as well) in years of construction. When I moved here I couldn't call myself conversationally fluent (I am now) - I hadn't spoken Spanish in probably 20 years and forgot a bit. I had the damndest time understanding what people were saying here for quite awhile and with a real strong accent I still have some problems (mostly on the phone with no cues to go by) even today, and I speak Spanish almost all the time, and am even starting to think in Spanish. I think one of the reasons I write so much here is that I go days sometimes without speaking a word of English! But my family speaks with a Paraguayan tone which is much closer to the Mexican I'm used to (and the Paraguayan accent is really quite a bit different than Mexican, it's just that the Porteño is THAT much different in some key places).
One of the guys who travels a lot to Medellin has complained on numerous occasions how many problems he has with the Colombians understanding him. To be honest, he doesn't speak here well at all, but he can communicate fairly well with Porteños here because he is at least attempting to mimic the accent to some degree. When he mimics the same accent in Medellin the combination of the different accent and his poor pronunciation makes a big difference.
Porteños don't seem to have much of a problem understanding other Spanish accents and not at all with different forms such as "tu" vs "vos". Learn in Colombia and then visit Argentina and add to your vocabulary. But your first impression of the language, in my opinion, should be a more standard pronunciation.
On Spanish, if that is a (I know, not the only one) primary motivation, I'd have to vote for Colombia.
Nothing at all against the Porteño accent, but from pure ability to be understood, learning a new language, you'd be far better off learning a more common Spanish first. I first learned Spanish some 30+ years ago in Texas, first in high school then working alongside Latino laborers (mostly Mexican, but many Central Americans as well) in years of construction. When I moved here I couldn't call myself conversationally fluent (I am now) - I hadn't spoken Spanish in probably 20 years and forgot a bit. I had the damndest time understanding what people were saying here for quite awhile and with a real strong accent I still have some problems (mostly on the phone with no cues to go by) even today, and I speak Spanish almost all the time, and am even starting to think in Spanish. I think one of the reasons I write so much here is that I go days sometimes without speaking a word of English! But my family speaks with a Paraguayan tone which is much closer to the Mexican I'm used to (and the Paraguayan accent is really quite a bit different than Mexican, it's just that the Porteño is THAT much different in some key places).
One of the guys who travels a lot to Medellin has complained on numerous occasions how many problems he has with the Colombians understanding him. To be honest, he doesn't speak here well at all, but he can communicate fairly well with Porteños here because he is at least attempting to mimic the accent to some degree. When he mimics the same accent in Medellin the combination of the different accent and his poor pronunciation makes a big difference.
Porteños don't seem to have much of a problem understanding other Spanish accents and not at all with different forms such as "tu" vs "vos". Learn in Colombia and then visit Argentina and add to your vocabulary. But your first impression of the language, in my opinion, should be a more standard pronunciation.
