The increased cash flow would make such a substantial difference in your daily life that not paying it off would be foolish.Outside of that, I can't see many reasons I would take a 15% tax hit to save 4% on a mortgage, which is really only effectively about 3-3.5% depending on your tax bracket.

Quote from @Paul Lucenti: Creative methods tend to increase risk.

If you have a high level of faith in the company you are working with, then time will do what it is supposed to do and increase your IRR.  

That's your cost. 

The very tragic LA fires have generated a lot of discussion about insurance costs.

Especially for the cost.

Code enforcement in Coronado is stricter than the rest of the city, and it does fall under the coastal commission jurisdiction.Depending on the parameters of the flip you can safely factor for an increase in your timeline for permitting of about 30 days. 

I still think it is a good area to invest in despite the increases in cost.  

But I’d also buy the $200 5 year warranty.My last/only stackable I bought last year was LG, the combined towers to try to reduce noise, increase ease of use, and presents higher end look.

Most cost segregation firms will provide a free cost/benefit analysis quote to help you determine if the tax benefits from the study will outweigh the costs.