What are the specific instances when losing ~15% of your MR points is beneficial by using this method to get them into US?
I do recall there may be some fees that AC charges on some international flights that perhaps US does not charge which would make this transfer worthwhile?
I have a lot of MR points, and was planning to just use them on AC for *A international travel in business or first, so would love to hear if there are better options through US that make more sense, taking into account losing ~15% of your MR points to do so.