How close are you to getting LT Marriott status? IOW, is it attainable within the next year? If not, I wouldn't worry about it and would charge to the card that gets me the most points toward awards. No one really knows how or what the LT requirements will be when the programs are combined, nor exactly how Marriott will finally "combine" the two accounts. While I "think" the most likely scenario is they will just combine the total number of LT points and nights, that is just a guess on my part. The only statement we have from Marriott is that if you have LT status in either program, they won't take that away from you in the new program. Since we just don't know what is going to happen other than that, I wouldn't change my points/stay/charging patterns for something I have no real idea what it will look like when the programs combine.