This is a broad question , not a black and white answer.   

.: black swan events, local socialists implementing rent control, local and federal governments taxing the crap out of landlords, a toxic dump discovered under your property, and plenty of other 'unforseen' surprises.

Black Diamond this month is in Waltham on December 12, there is a write up on the BP events page.

You actually live up in Black Hawk?

You do luckily have one very good one fairly close in the Black Diamond event in Worcester.  

I'd also recommend the Black Diamond meeting in Waltham which is a bit of a trek for you but is definitely my favorite one.

Stainless Steel,Black or White?)

I think as long as the numbers make sense and you're in the black on a monthly basis, nobody will fault you for buying something in your comfort zone. 

I learned after the first tenant to hire a pool service and build that cost into the rent after I got the house back the pool was black and full of frogs.  

Very active on BP and in MA, NH markets and also one of the founders of Black Diamond REIA.We have not personally worked with Ann (yet!)