Someone else here may know that part better than me.

Your situation is probably better for seeking out "Non-QM Lenders" or potentially other "Creative Financing" options

I've personally worked with a handful of "investor-friendly" lenders, primarily on DSCR loans in recent years, and each time I've run into significant delays, lack of transparency about the process, have been fed the requirements in a piecemeal fashion (every few days there's a new random request rather than having it all organized from the start), and have even run into lenders who were substantially misinformed about the real estate industry or the laws that govern it on both a local and federal level.I think there should be a better site to encourage accountability by tracking how long it actually takes each lender to close their loans on average, and what unexpected hurdles investors encounter when trying to work with them.I can't seem to find such a site.

Any tools or methods you recommend for better efficiency and transparency?

The Winter Park area) Larger properties do better and have a better chance of creating more/greater cash flow.

If you buy a package of 6 lesser houses  that means I have 6 roofs, 6 hvac, less cashflow, and likely subpar appreciation(dollar for dollar) compared to better areas.The reduced maintenance costs, higher rents, better tenants, appreciation, and reduced hassle factor for new construction are real and attractive.  

Which is better?

I agree that making the bathroom match the rest of the house will look better. 

As there were better deals out there.

This also leads owners to ASSUME simpler is better when it comes to management contracts.