Arguably, you may still be able to get some of that end game raid rush feeling. You just won't find much of the sentiment here on these forums, and would have to look elsewhere to find anyone likeminded looking for that world first progression style. But, I'm not familiar with older MMOs. It may also be you just won't find the same levels of difficulty here. From what little I've paid attention to, most of the "world firsts" for the game happen in the span of some hours to a couple days. At that point, yeah, likely it just becomes grinding for a piece of gear, to make grinding for the next piece of gear a little easier, making the next piece of gear a bit easier still, until you're all geared up, with nothing to really test it out on, until the next patch when you start all over. Although, I believe maybe the Ultimate fights exist somewhat outside the gear treadmill. Ultimates may be the closest thing you'll get to that old feeling, but they may not prove as satisfying.