My experience w/ small-time landlords has been pretty good. If you're quiet & reliably pay, they're less eager to jack up your rent because they don't want the pain of finding another decent tenant. Corporate landlords OTOH, will bloodlessly apply their algorithm and find your exact pain point.
I've had good experience as well, though I will say it's mostly been luck. Our landlords in Palestine were buying and renovating houses for rentals as their retirement and did a dang good job. Our current landlord has 3 or 4 properties and is perfectly fine to deal with.
But I also used to work in insurance and my goodness the number of slum lords I met out here. And they were perfectly happy to be a slumlord and they knew it. One or two were pastors.
I've rented most of my adult life and have had good and bad of both. Currently renting a house from a local couple and they are by far the best landlords I've ever had for precisely the reasons you cite.
Corporate landlords tend to all operate the same, there is a huge diversity of small holders, I know small holders that rent below market essentially per contract, I know small holders that troll rental listing and adjust every year