For me personally, it's about the feeling of progress (or lackthereof.). And I mean that in more than just one way. Yes, there's always the experience-related issue, but there's also the fact that often times it can take an hour or two to clear one tough snell. In fact, many times you never end up clearing that snell, because it's just THAT bad. That makes you feel as though you are wasting your time, a rather unpleasant feeling.
So anyway, ... my personal idea list,...
• Greater Death spawns should be "rare" and only occur in singles. Twin, triplet and quadruplet spawns of them are impossible 99% of the time, even if you have a bloodblader. And if they're beyond an unlurable snell boundary, such as the sphere crossing borders, they're literally impossible 100% of the time. EP is not a controlled environment, like the Dark Temple. Comparing group killings of GDs there to them in EP isn't realistic.
• Ethereal Wurm exp should be increased... I've ran into a bunch of them a few times and not only did they force the group to retreat one time and almost killed them the other, they were all "slaughters" for Kerrah and I. This was several months ago. While their burst damage isn't all that high, the fact that they're fast, can hit almost anyone in the game, can brick most people and swing consistently means they're a very very real, hard to deal with threat no matter who you are.
• I think ethereal exp could be increased marginally across the board. While there are some exceptions, like Abyssal Hunters and Frozen Abyssal Hunters, these are few and far between to satisfy the thirsts of older players, who are usually instrumental in EP runs. We also have to keep in mind that unlike with most areas you can't lure one thing at a time in EP. Which means that the difficulty to kill things is much higher. So ideally the exp would reflect this.
• If the sphere "border" snells could be less dangerous than the non border snells, this would help a lot. The nonlurability of these snells more often than not means that hunts/trips end there also.
Anyway, that's *probably* pretty close to my ideal list. There are most likely a couple more things I could mention but they're more nitpicky.