DSCR loan, bank statement loan, Seller finance, etc.. there are a lot of ways you can secure the property without needing input from DTI.

I have been given a few names: Equity Trust, Pacific Premier Bank, Midland Trust, Entrust Group, but I am not sure who to go with. 

As I stated above this does not matter because banks and brokers do a lot of different gimmicks to try and make their rate look better. 

Specifically, we’ll compare DSCR refinance loans to traditional options, namely bank or conventional loans.

The bank used a comparable sales model.

Fannie Mae, Freddie Mac SBL, Private Money, Commercial DSCR loans, Local Commercial Banks etc.. 

Depending on the state or jurisdiction where you reside this is a fairly simple process.  

It depends on the Bank.

Two different banks, four different closing companies (because three of the sellers wanted to solely use their own companies). 

I think you are on the right track comparing options - however I would note that there isn't really a differentiation between "DCSR" and "ARM" - there are a lot of 5 Year ARM options for DSCR Loans so theres overlap - maybe you are referring to a true 5-year balloon bank/credit union type loan?