@Ivan A. I would not recommend assuming the construction of the remaining portions of the Beltline will provide even a fraction of the benefits financially as the Inman park / Reynoldstown areas. This pricing 'explosion' (not implosion) was due to a perfect storm of variables and more the reason why the Beltline committee chose that specific area to construct first.
The constructed Beltline area as it stands has always had phenomenal walk-ability and has above average public schools for Atlanta which is why gentrification has happened so rapidly. The crime scores and areas that have been 'rougher' were much smaller in size as well.
The south-western portion of the Beltline has already had investors over populate the market. Residents understand what is going on and over the past 1.5 years, home prices have doubled while rent values remain the same. This area will be extremely hard to cash flow a portfolio positively. It will also be at least 3 years until the current Inman park Beltline portion connects to the south western Beltline where Stream Reality Partners is development the beer gardens. There will be a large gap in this area as gentrification tries to take hold yet rents will not rise - it would take a massive effort in a demographic shift to have a resident willing to pay rents that match some of the home prices that are now popping up.
The true portion of West Midtown where Westside provisions does not scare investors away. There is a huge lack in SFR in this area (unlike Inman) and thusly multifamily has been taking off. The construction of the Beltline is far out in this area but I do think it is poised for the biggest growth aside from Inman.
The areas around the Dome have been purchased for the past year and probably provide your best option for cash flowing for 8 years IMO. I would recommend looking in this area as most of our clients try to do what you are doing and it sounds great in theory but in practice its much tougher given the fact that everyone knows Atlanta has a hot market.
Regardless, good luck and hope you find what you're looking for!