I just use borax now. I've never tried them together. The store where I live has borax, but I used to use the washing soda because that was available to me where I used to live. I don't really notice a difference between the two. When we used the washing soda, my husband said he didn't think it got his clothing as clean as the other stuff (All free and clear). When we moved here, I just got some All and stuck it in the cabinet with the borax but I don't use it. My husband hasn't complained, since he doesn't really know.
I don't have a front-loading washer. I don't see why it wouldn't work just as well. Aren't those supposed to clean even better than the top-loading ones? For $2, I think it's worth a try. You can use it to clean floors or whatever else if you don't like it for your clothing. It's an "all-purpose cleaner', but it's not good as a de-greaser.