my first multi family, non-owner-occupied (a 4-plex) needed 25% down and normal conventional loan qualifications (purchased November 2014). 

Do we invest in a 3-4 unit older home with good rental history but probably needs quite a bit of maintenance (and might not attract the best quality tenants at the rental price point) or do we go with a newer duplex that is basically turn-key but doesn't have a rental history because both sides were owner-occupied?

I live 9 months of the year over seas but would occupy the home for 3 months a year.  

Consider any due on sale clause filing an option.Owner occupied, have a mortgage originator qualify the buyer.Do not put contingencies in an option that require performance, like paying rents agreed, it will invalidate the option making it a purchase contract, an optionee may not be required to perform in any aspect under an option.The lease and option are separate contracts, the lease may require performance, like paying rents as agreed.A residential tenant may not be responsible for repairs, IRS requirements.On a 3 year option, it will be better if you were to pay $3,600 as seller concessions to closing costs, she must pay pre-paids under most mortgages.

The other thing I noticed is it's listed as owner occupied on the county assessment. 

Most HML's wont do owner occupied because of the different rules and licensing, plus paying 3-4 points on $600k would hurt. 

He has kept expenses reasonable and the apartments occupied. 

Scott The Book on Flipping Houses, The Book on Estimating ReHab Costs http://www.biggerpockets.com/flippingbookConsider checking out HUD homes for small multi's owner occupied gets first crack.Download BP’s newest book here some good due diligence in Chapter 10.

@Valinda Horstman We used these guys to help us understand our options when we purchased an occupied property at auction. 

The bank has no control over the occupancy, and Always would rather have an occupied property.