Just to touch on what Ben Leybovich mentioned, knowing yourself and your goals will be vital in determining your strategy.

I need to figure this out as we are looking at our 5th property at the moment and I'd prefer to have that extra layer of protection on each one. 

@Tyrone I am in the camp that believes that an LLC is an unnecessary layer of complication until you go commercial, have 5 plus properties or like your case have an outside party in your deals.  

It works great by providing that secondary layer of asset protection, and taxes are as simple as a 1065 and a pairof K1s.

It would give you a layer of anonymity and add outside liability protection.For putting assets in the LLC you just do an assignment that will be your contributions to the LLC.

By forming a LLC you are adding one more layer of protection between your business and personal assets.

Supposedly an added layer of liability protection.    

An LLC can offer an additional layer of protection.

@Thomas Kwan  While I have never come across a 401k being pierced since it falls under the trust umbrella for lawsuits brought against the plan assets, some will invest the solo 401k funds in an LLC thinking that they will get an extra layer of protection. 

It takes 3 layers and each layer needs to be dried in between.