I have seen and heard of many bigger companies acquiring these houses very fast and efficiently and I was wondering if anybody knew what they do so I can learn as much as possible.

If you are buying them off the MLS...then a lot of banks can do that reasonably efficiently.  

We plan on replacing all of the windows for energy efficiency.

Connect with other landlords and see what systems and processes are they using in their business to allow them to manage the property efficiently

Cons - lesser quality control, more prone to mistakes, fewer efficiency, inability to scale.

Shafi, unfortunately, the SFR experience doesn't always efficiently transfer to MF experience. 

Most of our value will be through operational efficiencies.

I'm surprised by how much this is for such a short period of time (also looked at 12 month at lower monthly rate but that adds up to even more) for a "trial" to live in FL.The condo that we would purchase we prefer something simple and efficient below $150k and have even seen some potential options  below $100k - seeking a 2/2 single story, first floor, pet friendly from PBI area down to Del Ray without golf club membership required.

I don’t know about property management but if some people are doing it, then maybe they have a more automated or efficient process.

Alternatively, you could also do electric base board heaters which require very little maintenance, but are not as efficient.