Regarding applying for citizenship, CABA has the lowest thresholds to be able to apply, you don't even need to have a DNI. Whereas outside CABA, especially in more remote provinces a DNI is required to even start a citizenship case, which means you'd need to wait however many months for Migraciones to approve your residency application, and then send you a DNI in the mail.
Some of the remote provinces can move faster once you apply for citizenship, but don't forget that in CABA you're going to have a multimonth headstart because you can apply without a DNI. Also any kind of lawyers, accountants etc that you'd need to help you apply for citizenship will all be in CABA. In a remote province, you're more or less on your own in terms of professional assistance.
