You gain flexibility in that you can now gather marks on, say your titan, and use those marks to buy armor on your hunter. This is important because the grind to 40 will probably be a real b**ch, while the most heavily mark-rewarding activities are sure to be on the high end. Getting one there will support working on the others. Another nice perk is that even just grinding the little daily activities will get you enough for a mark purchase fairly quickly now. Before, those 5 mark rewards from dailies could take a while to add up. Now you can reach rewards faster if you like to divide your time amongst your guardians evenly. The downside is that your effective mark limit is a sixth of what it was before. This is irrelevant if you're fine spending your marks as you go, and only really serves to limit players from storing up marks for mass gear purchases on release of a new DLC. Keep in mind that there is [i]no[/i] weekly limit on marks now, so the collective pool has no downside there. On the whole, it's a nice change in my opinion.