I have done both and I'm back to self-relaxing. I started with self-relaxing. I then found a salon that would let me bring in the Phyto. She charged me the same price. I thought they should at least drop the price a few dollars, since they weren't supplying the product.
So, I then found an Italian girl, who flat irons like crazy. She has a black clientele. Her salon used Phyto, but she really wasn't very good at smoothing the relaxer. So, I had her apply a 2 instead of a 1. The hair was straight, bone straight.
Now, several months later, I'm back to self-applying Index 1. I like the body and the wave in my hair with Index 1. So, if I ever go back to a salon application, it will have to be with someone who is VERY good at applying relaxers and charges a fair price when they are not supplying the product.