As you get more experienced at this and in the sound you are hoping to achieve, you will generally get little to no satisfaction when you upgrade slightly or it was a sideways move. I like what the reviewer for Dagogo, Doug Schroeder, said about upgrading cables or really anything in the system. He says if you have to strain to even think you are hearing a difference for the better, then it wasn't worth the time and money to do it. He won't upgrade to a better cable unless it is significantly better in sound--and, for the most part, it will also be a significant jump in price, too. I putzed around for awhile with very slight upgrades or some changes that weren't even noticeable. It was when I started doing what Doug suggested to me--upping the cost about 50%--that the changes made a significant difference. I'll agree with those that said it depends on the sound of the system whether staying with one brand of cable is a good idea or maybe throwing a different brand in the mix that has strengths that go with the different strengths of the cable you already have and liked might be a better way to go.
Bob