I'm looking to scale/upgrade to a larger home for a second property, but seems like no matter which way I look I'm at some sort of roadblock or disadvantage.

This gives the OOS investor a built-in disadvantage over local investors.

As a wholesaler, hopefully hearing from some of you with experience with these sites, what are the advantages or disadvantages of each of these sites respectively... as far as which search criteria to use on each platform?

I believe there are more advantages than disadvantages. 

Avoid PMI and then go to a local credit union and get a heloc after closing to gift the money back.Have this as a tool in your tool belt but pursue use of the 3.5% FHA, knowing that you will be at a competitive disadvantage if you are competing with non FHA buyers, then you can call in the favor from your gift person.Just know that if someone gifts you down payment money, your bank will require them to sign a letter stating that it is in fact a gift that doesn’t need to be paid back.

What can be the disadvantage to keep it aggregated in the coming years?

Next, decide on what type of asset you want to invest in (single family / multi-family - both have advantages & disadvantages).

Having appliances is much more of a plus than a disadvantage.

An advantage was that if your clothes could be tumble dried, you could simply turn it on to wash and dry, and it would go through the whole cycle without needing to move anything from the washer to the dryer.The disadvantage?

While living in high cost cities has its own advantages, one of the disadvantages is the high investment cost it takes to enter into real estate investing.