For ROI, don't forget to factor in how much the house has appreciated while you've held onto it and mortgage paydown-ie don't just look at rental income vs your initial down payment. 

We have occasionally run into issues with the Internet being down at the STR and it not all going through with a tenant now using a code that doesn't work.

Sure it has potential for cash flow, appreciation including forced appreciation, tax benefits, mortgage pay down but in most markets it is the leverage that accounts for the significant return.  

I'm willing to bet if rates went down significantly than getting this property under contract would have had even more competition.

But then it was a nightmare of communication, we soon realized that we had to do a bunch of songs and dances to convince them to sponsor our deal, it took 4 or 5 days for them to make time to sit down with us only to tell us that we needed to schedule another meeting in another 4 or 5 days to get Tyler on the phone and let us try and convince them to sponsor us and by that time someone else was awarded the deal and we lost out.

50% down is considerable but common.

I have the reserves in place for the 5% down payment, 15K for emergencies, and have no debts!

I was able to take a loan on my 401k to help pay down our house, but I was recently fully disabled so there wasn't any penalties for us.Get a good CPA and get started.Plus you could always wait a bit and not move on any more properties until you get all this under control.

The county assesses those lots as worth about 10K, but when houses burn down in the neighborhoods where I have houses, the rarely rebuild them.

Even if you have the money to put down on your deals.