I run one. It's the only filtration I have. My experience has been so-so, but that's probably due more to my tinkering with everything than with the scrubber itself.
A waterfall design using the standards on algaescrubber.net will work, and unless you are feeding a ton, they can be pretty compact.
You can put a simple one together for almost nothing, so it's pretty easy and low risk to try.
Mine has no salt creep, is super easy to maintain, and runs off my drains, so there's no extra pump. It's literally a $7 plastic target magazine rack that the drain runs into, water flows over the side across a $1 piece of plastic mesh and into my sump.
My tank is a mess though, so you might not want to take any advice from me...