@Patrick Lismon When I see cap 15% cap rates being thrown around, I am automatically skeptical of the expense ratio & suspect key expense inputs are missing.

OP cap rates are fairly meaningless.  

If you're going to put in the effort, get the most bang.  1. 

Three core metrics will tell you 80% of what you need to know about a deal: Cap Rate, Cash-on-Cash Return (CoC), and Debt Service Coverage Ratio (DSCR).Let’s break them down simply:Cap Rate = NOI ÷ Purchase PriceThis is the market’s ruler.

They also have a lower ROI/bang-for-your-buck than aesthetic upgrades that are easier to see and enjoy.

The bang for the buck is there but if I could get something better for the tenant communication aspect, that would be highly recommended. 

What would you consider to be the best bang for your buck security system for short term rentals?

That’s your best bang for your buck right now.

They are buying at a 5 % cap rate with a fixed 5.7% loan amortized at 30yrs and first 2 yrs interest only, and they believe that they will sell at a 5% cap rate as well 5 long years from now.

It looks like your options are a Cap Rate valuation or a manual override.