Beach Hostel or DownTown Hostel?

Hi Hostel Management comunnity,
mi wife and i we have been working in Boutiques Hotels in Cartagena Colombia for more than 5 years, we are quiting our jobs to open a Hostel but we have a little dilemma, we found two houses to star our Hostel Both have the same prices for rent. I will describe both of them.

the first one is on the Downtown its an old House with 620 mts2 with 2 floors, it is divided in 5 apartments only one is ready to work with 3 rooms the other apartments need money for adecuations and to start working, this house its ubicated 1 blok away from one known plaza of Cartagena wich is Plaza san Diego where is one Sofitels Hotel Santa Clara, but this street is not so comercial is more residencial, this plaza has some expensives restaurnats all around.

the second House has 450 mts2 and it 10 minutes away from the downTown, but this house is infront of the beach it has 5 rooms 4 with private bathrooms it has a big patio where we can put a pool, this house has everything my wife has dreamed but we are a little concern about the location because there are only 2 hostals in this area, but not whit the location like us, the other hostel are in DownTown.

so we wanna know if there is some preferences for staying infront of the beach or in Downtown?
all have free bikes for going around the city.
if you know a web page or a blog where i can make a survey about it, i will be really pleased.