I have used both. By the GA, Farmina Low Grain is more comparable to Acana than to Farmina GF. However, neither of the Farmina lines use lentils, peas, chick peas or plant products to the same extent as Acana. Farmina GF has much higher protein than Acana.
Pricewise, Farmina Low Grain is considerably less than Acana while Farmina GF is about the same price as Acana but the protein is much higher in Farmina GF.
I think the Cons with Acana is that you aren't get the animal protein you think you are because of all the label splitting of the plants ingredients, and your are paying top dollar for the food. The Pro is that it is easier to get than Farmina.
I think the Pro's with Farmina is that the foods are much simpler and use much more animal protein than Acana and the value is much better. Farmina Low Grain foods are $48 - $53 a bag online and GF foods are $64 to $78 online. The Con with Farmina is that its harder to get, but with Amazon Prime and SportDogFood.com and Chewy.com I wouldn't say its hard to get. In fact if you look at the locator map on the Farmina website it looks like stores are being added on a regular basis and its available now in Nebraska if you can believe it.
Personally, I think the Acana foods are very overpriced for a food with that protein level and foods that use lentils, peas and yadayadayada.
The dogs like Farmina better in my experience and the poo is much darker and smaller and they eat much less.