@Eric Shadowens, I have heard both good and bad investment stories related to these platforms. Fundrise offers proprietary "eREITs" or private REITs. RealCrowd offers direct deal syndication and private funds through third party sponsors (real estate operators), and Crowdstreet offers private REITs, direct deal syndication, and private funds through third party sponsors. As I'm sure you are aware of the three offering types, each have their pros and cons.
While private REITs can offer you good diversification across many properties, I would use caution with private REIT's as they are known to have higher fees than direct deals and private funds. They are also known to utilize some questionable distribution practices. When private non-traded REITs are first getting off the ground they may not have the cash flow to support the high distribution yield that they promise investors, do to this, some of these REITs have paid distributions entirely from new investor capital. Private non-traded REITs raised about $4.5 billion in 2016, a sharp decrease from almost $20 billion raised in 2013.
With direct deals I would advise putting a very large emphasis of your due diligence efforts on the sponsors because at the end of the day you are essentially investing in the sponsors expertise and ability to execute on the investment strategies that they are selling. As @Leslie Pappas mentioned above, if you are not comfortable with your own ability to conduct quality due diligence, it may be a good idea to bring in a professional third party to assist with this. Some of the stories I have heard about investors incurring massive losses happened mainly due to poor sponsors and lack of their ability to execute the business plans.
Similar to private REITs, private funds also offer diversification across many deals. However, because private funds are not required to pay out regular distributions like private REITs, there are no signs of the questionable payout practices using new investor capital with this investment vehicle. Private funds will also not include hefty up-front sales commissions like many private REITs do. With private funds it is also very important to make sure you are investing in a qualified sponsor, just like direct deals. There are private fund managers and sponsors out there today that have strong performance history and industry expertise, but have broken away from the crowdfunding platforms you asked about and gone towards sourcing new accredited investors from their own websites/platforms.
-Vince