Differences Between Multi-Family and Residential Income (5+)?

[Mike Goldenthal]

I've always been told that once you get above a 4-plex things tend to get a lot more complicated due to the classification change. Wondering how much truth there is to this and what the actual differences are between acquiring and maintaining a small multifamily and a larger complex (specifically looking more at 6-12 unit buildings for what it's worth). 

Would love if anyone had some insight into how these differed from smaller multi-family's as it pertains to 

-Acquiring financing/financing requirements/down payments

-Insurance

-Taxes

-Overall Maintenance

-Any other factors that you feel are significantly different.

Thanks!