(A multi-family, if you can afford it, achieves the same goal.)My two cents at least.

Managing an STR a very hands-on 24/7 job if properly managed with a decent occupancy rate.

Landlord might not want to remove them, and would be keen on keeping them, but at a new rate/terms. 

@Samuel Metcalf- sounds like you have a FHA loan as  PMI is permanent in most FHA loans ....I would ask  the bank that holds the loan for  refinance  options and then shop around to see if there are  any refinance options that  make sense ...if not - live with the loan you have  but be  ready to refinance  when rates drop 

Beyond rate, is there any cost difference between the two? 

So right now if someone wants to book 26/27 Apr we can upcharge 100% of the Thursday rate so essentially they pay for the 3rd night without realizing it, and it leaves that day open to be booked. 

Are there any resources where you can put your income, purchase price, down payment and credit score and see potential rates and which lenders do it?

@Cillian KellyI never do because my rate is 3%.

Also insurance rates are cheaper in SC than FL.

The property I've set my sights on is a 9-plex where the owners are willing to carry 70% of the loan at a 5.5% rate for a $1,800,000 building.