Mm.. because of my activity level I tend to have my sweets in the morning to replenish and build and then regular potatoes as night. Sometimes I roast the two together as a blend but lately have been switching off at night between roasted squash, Kabocha or Butternut, and the potato. A typical post WOD meal for me is roasted Japanese sweet potato, about four huge handfuls of greens, right now collards, braised and then a protein finishing with some sort of fruit to munch on - like a palate cleanser I guess. It works for me, I feel aces and have continued to stay lean, build muscle, be fast on my feet.
IMO just play with the two and see how you feel. My love for N=1 is neverending :)
Note: Comparison of the two - of course the sweet has more antioxidants and the gi level is lower, but it's interesting to see the two together:
7-ounce white potato with skin: 220 calories, 5g protein, 51g carbs, 20mg calcium, 115mg phosphorus, 2.8mg iron, 16mg sodium, 844mg potassium, 4g fiber, .22mg thiamin, .07mg riboflavin, 3.3mg niacin, 16mg vitamin C
7-ounce sweet potato: 208 calories, 3.5g protein, 49g carbs, 56mg calcium, 110mg phosphorus, 1mg iron, 20mg sodium, 693mg potassium, 5g fiber, 4350 RE vitamin A, .14mg thiamin, .13mg riboflavin, 1.2mg niacin, 49mg vitamin C.