You are right , lot of variables and a very difficult comparison, thanks for the tip, will search the forum 

I think comparing to the two-- syndications vs index funds-- is too difficult because of the nature of the specific RE under the syndication versus the broad economy(global and domestic) the index funds capture.

I have considered renting by the room but think it might make managing all the tenants difficult so I have tried to stay away from that option

I have been an agent for 35 years and started my investing career many years ago and am amazed that so few agents take advantage of the leverage and opportunities we have over others to build wealth and passive income. 

Understanding the power behind real estate investing has changed my life / career dreams.Sold a 2yr old new construction home in Westmont IL...

How do they get tenants in place, and how difficult is it really?

You haven't given many details so it's difficult to give you a quality answer for your situation.

Beyond being difficult to make the numbers work, it's just not a wise strategy IMO.

As an out of state investor, Birmingham has proven far and away my most difficult city to rent remotely (it's one of five cities in which I have rental properties), mostly because of terrible property managers.

That said, my last Booking.com guest a couple of weeks ago was a bit difficult pre-arrival but ended up being a great guest and left a 10 star review (no comments though).