My horses have done very well on the Safe Choice. I don't have any experience with the Triumph 12% Completel. However, I know years ago Triumph was not one of Nutrena's better feeds, that from a company rep directly to me when I was trying to choose a feed.
I switched to the Triumph this winter because my horses were not being used and it was a little cheaper. However since I am getting my barrel horse legged back up I went back to Safechoice. I prefer the 14% protein when I am using him. I didn't really notice a difference in them when they were on one feed vs the other but I was not doing anything with them either.
I only have a choice between Purina and Nutrena feeds. I switched from Strategy to Safechoice last year. I believe it was because the Safechoice was a little higher in fat. My horses look great and my barrel horse was running great so I am happy with my choice.
I fed the triumph for about 2 years and I switched the safechoice orinigal a year ago due to the high molasses content of the triumph. My horses love the safechoice and I'm feeding half the amount of safechoice as I was of triumph! And horses are still in good shape!