But that's in the current economic climate.

I have seen these units work in small areas in moderate weather but can they work in cold climates in the north east?

I would want to soak up as much information as possible and truly become a student of this business as well as someone who understands the climate of it's up's and down's.  

And when the achievement finally happens, it's short-lived, anti-climatic, and they end up raising the bar anyway for the next goal.Focus and celebrate getting in the gym each day rather than focusing on the size of your biceps.  

Around here that is what I believe to be a really great return provided you can have your offer accepted in this competitive climate.

In todays climate Class A rarely meets the 1% rule.

I realize the apartments would be a more stable investment but I feel like the hotel industry, especially in certain areas/climates, has the potential to provide a serious income.

I doubt if we have the hardness you recorded but yearly preventative maintenance of any system is imperative to longevity.Given the precarious attic location I would definitely review the obvious advantages of an on-demand system.I have also designed a simple fix for the 'cold water sandwiching' issue that plagues the on-demand systems with feed water temperature fluctuations common in colder climates. 

I've seen to many people try to DIY plumbing and get burned a few weeks later when they forgot to do something like re-wrap the pipes in cold climates...

My story sounds similar to yours, except that I did mine in the cold climate, the Winter Park, CO area.