Admittedly, they seem a bit sketchy,My question would be, for a person such as my self, how does one go about vetting these syndicates?  

At one point years ago, I toyed with the idea of owning giant apartment complexes in multiple cities.

As our team has grown, it's become easier to cover responsibilities if someone quits, goes on vacation, or if we terminate employment, compared to when we had one or two homes. 

You would want to look for an owner that has a loan through a bank or credit union or one that has no mortgage. 

I hear about all these different markets and get excited, but I knew I needed to pick one.

In one town where we had 12 rental houses, every one was sold to owner occupants, not landlords.

Cold calling is already such a poor-performing strategy. the ONE thing good about cold calling is that you are talking to a HUMAN, building rapport, and asking and answering questions.Now that ONE good thing about it is taken away...Like David above me, no experience, and it would indeed be interesting to see how it does, but that doesn't take away from what I mentioned above.

The house is worth around 900K, my share is one sixth of this at around 150K.

If there is no explanation, ask for one]Why on Earth is YOUR LLC owed money by 200 Walnut Street LLC?  

Quote from @Ogonna Odo:  Small ones will not, they typically like cash or checks.