Have rented twice from LandLord. First time I just responded to an online ad. They showed me the unit, though I ultimately settled on the second one they showed me.
When I changed jobs they helped me find a great place that was close to my new work. They knew that I'd also recently got engaged, so helped me find a place that would be suitable for me longer-term.
Only issue I ever had was during the ice storm my heating was knocked out for a while. They were responsive, and I've never had a complaint.
Before renting through them, I'd rented direct from a home owner. Much prefer having a pro on the other end of the phone/email.