Every other NPC that rewards you for quests tells you that your inventory is full, preventing you from collecting your reward. Xur, however, after hours of grinding to get a single exotic cipher, is just fine with telling you to shove it if your inventory is full and you just get to wait until next week to grind again? Are you freaking kidding me? It doesn't go to postmaster, he doesn't hang on to it while you delete one of the dozens of world materials we probably won't use anyway (or one of the absolutely useless tickets to nowhere that you keep giving us), it just disappears. Good job, you get nothing. The fact that this isn't an issue with any other quest line, yet it apparently has been screwing players over with Xur for years, means you intended for this or don't care enough to fix it. Fix it. We pay you too much for this crap.