I built my first scrubber on my old tank and it helped greatly in removing my algae - see my post at ReefAddicts for a detailed write up.
Then I had a scrubber built by Santa Monica nearly 2 years back. Had to change tanks, etc. - took a while to get everything set up. I've been running the scrubber now for about 6-7 months. My setup:
120 gal RR Oceanic Tech Tank
30 gal glass tank converted to a sump (adds about 15 gals of water)
26 gal secondary tank (frag outgrowth) plumbed into the same system
2 x 250 watt MH (each on for 6 hours)
2 vortech MP-40 pumps running on left/right sides of the tank
Feeding: 2 cubes of frozen food 3 times per week, 2x3" piece of seaweed 3 times per week
Fish:
1 Foxface rabbit fish
3 firefish
1 green chromis
2 true percs
1 goby
1 cleaner shrimp
1 coral-banded shrimp
Assortment of crabs and snails
I believe the design is the SM100.
Scrubber lights are opposite of the main tank. 18 hours on, 6 hours off.
There are two fixtures, each 54W of light with bulbs provided by SM.
Dedicated Quiet One 4000 water pump (about 1,000 gph)
Water level in the scrubber is at about 1 1/2 inches
Mostly I am getting yellowish/brownish growth, very little of it.
Scrubber is cleaned every 8-10 days.
I definitely have more algae in the main tank each week - I've removed giant chunks of it and about once a month I have to scrub the rocks so that at least some of the corals survive.
Images - click to enlarge
1) 9 days of growth - this is about the most I've ever seen on this scrubber
2) Second section - interestingly, notice that where the water flow is slightly less (below the zip tie), greener algae grows
3) After cleaning
Hoping that the collective experience can provide some insights soon. I'm happy to provide any additional information needed. Thanks!