If we take into account the above assumptions that the deal make sense, in 30 years, when the loan is paid off, the larger deal would have generated a substantially higher amount of profit and net worth to the owner. 

Buying land to build anything outside of a stick built home is often too problematic thanks to the bureaucracy of the anti-development local government here...Perhaps consider buying a larger MFR with a partner down here? 

Your choice.

Being primary residence you can get better rates and larger amounts. 

A syndication is very unlikely to have no debt).On the other hand, syndications allow most investors to access and diversify into asset classes that they would not be able to own on their own because the entry point is too high (ie, offices, mobile home parks, self storage facilities, larger multifamily etc.).

You have to make that choice for yourself.

You're biggest choice is going to be area, and Townhouse or Single family. 

We are still buying but are slowing down  some and putting down larger payments as well as looking to free up cash. 

I’d be interested in collecting an opinion or two from people that have made this choice before...I’ve collected about a dozen SFR rentals and I’m considering selling one.

Some comments on what @Mike S. and @John Morgan said.Yes use a warranty deed to transfer the title (actually a special warranty deed may be a better choice.