The interest rate is not special nor is the 20% down (80% LTV).  

This is to get your tax deduction at a higher tax rate.  

Working with a mortgage broker that specializes in DSCR loans will help you find better rates and programs such as lower DSCR ratios such as a DSCR 1 ratio for better terms versus needing a 1.2 or 1.25 DSCR ratio (more on that below).

You can find out nightly rates, occupancy and amenities.

Lastly, the price point is still very cheap here in the sense that you can still find investment deals that hit the 1% rule for 120-180k!

While a western WA deal might not meet some Midwest cf metric like 1%, it will be above the market cap rate or below FMV of comparibles and give you options. 

Also, I would look at rental rates to property values to determine if any areas are around the 1% rule.

In San Diego at the current rates for a purchase loan (which has better rates than an ADU additions) at high LTV, I show 1% does not cash flow on a sustained basis.  

Those sounds like great rentals and vacancy rates have been decent - our management team only has a handful of vacanies out of the 300+ we oversee, thankful for that.

The lower rate or longer term can also make the payment more affordable.