A kid who works for me loves it. He wanted to give it a try on a very
large / simple room (~25 x 35')
It's rather messy to clean up but with latex paint it's not too bad.
You can really lay down the paint because of all the time you save not
having to "recharge" the roller. We don't paint large areas very
often. How much paint do you envision using?
For a few 100 ft^2 I'd stick with a regular roller.
I helped my son do his garage interior (primed & painted bare drywall)
& didn't use it. It would have been perfect application for it.