Most (all?) of these companies have not been through a complete credit cycle since they were founded after 2008. I would be cautious about putting money into them that you cannot afford to lose.

Only after they go through a full credit cycle from boom to bust will you know how well they have managed risk and leverage. If they are transparent enough for you to be able to do the due diligence on their assets and leverage (and you have the expertise) you should probably wait and see how they do during the next recession.

I would also suggest you ask the question why would you would invest in them as opposed to using more traditional REIT or investing in real estate yourself if you are so inclined. Is it because you are expecting a greater long term return and you think they might be able to provide it? Again, I would wait and see how they do in the next recession (or credit crisis) to get more realistic view of their long term return profile.