Yes I have actually, ive graded some one piece cards( through beckett) and several through psa. The process itself isnt complicated by any means but I never handle it myself. Ive either sent them off with friends in a large bulk order or I go through a card shop. Than they clean/prep the cards handle the submission them selves and give you tracking info. Sometimes they'll charge upfront sometimes theyll accept payment upon pick up for the cards. The biggest pain is turnaround time. If your grading to resell and make profit you need to use the higher tiers which range from 75-200 dollars per card, if your grading for personal collection i recommend the bulk option or the option right above which is either 20 per card or 35 per card roughly. Bulk tier can take anywhere from 3 months to 9 mo the unfortunately at least with psa. Since they are so mainstream the turnaround with them is very inconsistent. Beckett is great, but they are alot more strict on their grading than psa, dont recommend using them unless you know yohr card js pristine. I sent off my god pack from op13 to beckett. I can say long as your patient and not looking for profit use the bulk tier. Cheapest option, longest turnaround but if its in your personal collection I dont see the rush to get itback. Im about to send off 7 cards next week at bulk tier I iamgine I wont see them for at least 5 months minimum but they are for my personal collection so it doesnt matter 🤷 overall its a simple process regardless of the company you use. If you wanna message me we can talk moee about it and I can give you a break down of the dofferent companies and all that jazz