Otherwise I'd say it's like any big v small experience. A small landlord is like any small business - can be great or dire and somewhat erratic.
The big ones are much better at scaling stuff, often better at compliance, but that doesn't mean the experience is any good - merely more predictable across that business.
The people who had this mastered (before thatcher wrecked the UK) were the councils. Long runs of identical housing, standard parts, bulk upgrading etc