I don't believe Ecotrition has any good products for any creatures. Their rabbit food is horrible - rabbits aren't meant to eats nuts and seeds and the other stuff they throw in there, same thing applies to their guinea pig food.
It's nice their organic formula doesn't have any preservatives or other junk in it...but as far as I'm concerned, I'd stay away from brands that have a balance beam of products. One one side of the balance beam they have products that are horrible, contain preservatives like ethoxyquin and BHA/BHT which are just plain deadly... and on the other side of the balance beam have products that seem to be pretty good.
I don't trust companies, like Ecotrition and Kaytee, and Sunseed, etc etc who try and pump up their trustworthy image by coming out with "good" foods, yet still leaving their bad foods on shelves.
If you want a pet food company that has started off well, and continues to do well, look into Oxbow's "Healthy Handfuls" obviously, it would need to be supplemented, ideally(in my opinion) with a Supreme Pet Foods inc. product catered towards gerbils, but anything is better(in my opinion), than Kaytee, and Ecotrition and Sunseed, and VitaKraft, and Hartz..and all those other poor brands.
Also, keep in mind gerbils, like many other critters are food junkies. Their food should NOT contain sunflower seeds. If they DO get sunflower seeds, they need to be fed ONLY as a treat, and ONLY sparingly.
Again, in my honest opinion, I wouldn't promote a pet food company who has a product line that varies so drastically between being deathly dangerous, and awesomely good.
Whatever you do, make sure your gerbil food does NOT contain ethoxyquin/BHA/BHT, or sunflower seeds.