Does anyone have experience with the 203k program that could shed more light on the benefits and drawbacks?  

The main drawback to commercial multifamily is that it takes a lot more money to get into.You also want to consider what "grade" of property you want to invest in.

I have even tried to not accept the commission in lieu of a lower purchase price, and have been told the commission is not negotiable, it does however subject me to self employment tax on my flips, as a broker/dealer. but the drawbacks are way less than the rewards.

What are some of the drawbacks and advantages for each?

The drawback is trying to convince a potential tenant that your rental is worth the additional rent.  

I think the biggest drawback to the 9 to 5 job is giving up on your goals. 

There are some drawbacks, I occasionally have tight months where cash flow is not good. 

Once the industry develops a robust secondary market the major drawbacks of private securities will be removed.

Any drawback to this?

Any drawbacks or specific advantages?