I have over 10 properties with a partner.

The reason why I decided on Baltimore is because my friend-partner lives there and he had done 20+ flips in the last 3-4 years. 

Also, the state of formation is likely where internal disputes would be brought among LLC members, so if you and a partner and/or spouse live in CA, you probably want to arbitrate in CA if the two of you had a disagreement.

I looking at how I can enter the US REI and am considering partnering with a local investor.

@Tomas Nuno I have house hacked with 2 separate partners for almost 30 years.

@Jagjit SinghWe have partners who are foreign investors.

I build most of my projects myself but since I generally work with out of area investor partners on my projects, these costs are generally what any GC in this area would charge.

Partners are difficult to find as well because most people at networking events are either have no experience, looking to remain more passive or way too experienced and have their own dream time.

Don't do it yourself if you have a partner. 

My business partner and I are investors in the area as well.