@Camilo Restrepo, I don't have any opinion and, to be clear, I'm neither arguing with you nor trying to convince of anything. There are many opinions but there's only one set of facts. If you want to make a comparison, you can check Airdna. IMHO, your problem was not Mexico, it was Cancun. As I wrote in my first reply here, I'd never invest there in an STR. It makes no sense. I'm actually surprised you managed to get a 9% ROI but I guess that's thanks to you being a good operator and getting 95% occupancy as a result. You can't compete against the all-inclusives unless you offer complimentary food and booze or you're cheap, as you seem to be confirming.
This being said:
1) Properties in Mexico/Cancun trade in USD so you have no foreign exchange risk in Mexico while properties in Colombia are traded in COP, the Colombian peso, which has been tanking over the years, eliminating any hope for capital gains for American investors.
2) You can get a mortgage in Mexico but you can't in Colombia so even with lower revenue, Cancun would likely still be more profitable, even if you don't take capital gains into account.
3) The political risk is much higher in Colombia, especially at this present time.
Is Cartagena a bad investment? I don't think so if you're ok with the currency and political risks. But, like most people, I prefer Mexico. For the reasons I mentioned, there's no contest far as I'm concerned.
Anyway, the most important is that you seem to be doing well and be happy about it. Let's hope the COP stops to fall, in which case I'd be keen to invest more in Colombia.