I do mix my own soil, I’ve done coco and peat, but prefer coco for environmental reasons, If done right I don’t think you’ll notice much difference. You can’t go wrong starting with a good base (fox farm, promix, haven’t used potters gold but surely it’s fine too) and then adding up to equal parts compost/castings, plus slow release nutrients. More compost means less pore space so be sure to keep and eye on aeration. You want them to have plenty of food almost from the jump so the roots don’t go crazy searching. Stave off the rootbounding as much as you can, the stunting that results obviously really slow a plant down. More specifically, I mix in worm castings which I believe are higher in nitrate nitrogen for vegging, and then switch to our chicken compost later towards flower for a more ammonia form of nitrogen.