I was rather cynical about Paint Pod as well, until I borrowed one. We're painting every room in our house, and are about halfway through. The walls are painted a rather sludgy green colour that would be nice if there was more natural light, but looks dingy in a Victorian terrace. Typically, each room needs three coats before it covers properly. So in the past six months or so, I've done a lot of painting. At the end of a couple of days of using the paint pod, I bought one of my own.
A couple of observations:
1) Yes, rollers are easy, and fairly quick. With high walls and ceilings especially, it's noticable how much quicker the paint pod is. There's no bending down to reload a roller, no splatter or spray, you just keep rolling.
2) There's very little paint wastage.
3) You can lend the pod to friends and family, and you can sell or pass it on. We're ruined / junked plenty of conventional rollers, trays and brushes so far, but this thing seems to be made to last.
I'll be repainting a flat of ours in a few months, once the house is finished, so I'm fairly sure the Pod will get thoroughly used. I think it would have been better for Dulux to make a more robust, rentable version, however – they are a bit bulky.
HTH