Their regular chicken has spicy breading option, but for the sandwich they just do the spice in the sauce.Popeye's pissed me off when I first tried and ordered a spicy sandwich, hold the mayo. The cashier told me the mayo is the spice. There is no difference in the seasoning between regular and spicy. Big time no go for me. Need some heat in the breading. Ideally heat should be in a buttermilk bath the chicken sits in prior to breading.
I prefer a spicy sauce to a spicy breading because the sauce has the fat already in place to balance out the spice. But you can't do that on normal fried chicken because you're at risk of losing the crisp and crunch. But because it's spread on the bun, it works well.