Feet on the ground, even just once, can make a world of difference in RE since many markets are very different block to block. 

I am a condo-owner in Miami (2 blocks from Coral Gables).

We also look at the state of the block.  

This criteria varies greatly city to city and block to block even,  but you need to know beforehand or you are already done before the day you start. 

I know you didn't ask me, but unless you're in the next block, I wouldn't worry alot about the train noise.

@Priscila Parra i really like Ridgewood, especially if you are within 3-4 blocks of a subway stop.

There are several 6-12 plexes in the neighborhood, some even on the same block.

An investor purchased a house just down the block 2 years ago for the high $200's and sold it for just over $700k.  

I could have been buying apartment blocks with what I spent on planes but they do not bring me the joy of an aircraft.Just go through any apartment complex parking lot ...

dljoka-at-kw-dot-com , His name is Daniel, he works for Keller William in Medford, i dealt with him on a property ( i never bought it ) but he responds to you and was very helpful, this was last year i dealt with him and i have not talked to him since then. just check where you are buying there, values change dramatically from one block to the next in some areas.