Many of these companies try to exert extensive control and what sounds like a great opportunity on the front end could turn into a nightmare as you have to deal with unhappy rehabbers, investors, investor, etc. 

If you are not a Licensed Real Estate Agent, you cannot control money for someone else. 

Andy, Solo 401k plan is not for everyone (you must be self-employed or own a small business without full-time employees other than the business owner(s) and spouse), however if you qualify for it - in most cases it would be a much better choice for most people (you don't need a custodian with it, you don't need an LLC to gain the checkbook control, you can borrow from your plan up to $50K before retire, just to name a few advantages).

There are a certain set of risks and loss of control when dedicating yourself to cloud based, business critical, software. 

They are always the first to depreciate when the market takes a dip, they are always the last to appreciate when the market rises, and there are so many factors outside of your control from a value standpoint. 

We decided to start a Hardmoney company as I had owning one in SF Bay Area before . and since we did not need outside investors it was fine since we controlled it.

I had control over my agent but not the sellers agent.  

If it will make you insane to not be in control of your property (to the degree most would label the control factors), then don't do it.

Just got to find under-priced good ones.After the first time around, you will owe about $450k, but you will control property worth $600k = net $150k; an increase of 50% equity!

The funds are in the bank and I have checkbook control.