Hi Ambularose!
I 've been living in Cabo for 6 years, my wife and I decided to get married in Tulum last year.
For us it was for practical reasons, we are french and Tulum was closer than Cabo.
The 2 locations are amazing, Tulum is smaller, there are less hotel options, maybe not as many activities as in Cabo...
I guess you have to see what are your priorities and also consider your guests...
Let me know if you have any specific questions about the 2 locations, I'll be glad to help you!
Jeremy Herman