I live for endgame PvE. However, my feelings on 4-8 man PvE are different. I love group content (or I'd be playing a single player game), but not large-scale group content. I feel that low man content is much more epic than larger scale group content. Because large scale almost always ends up being a zerg for one. But also just having the bragging rights to take out some bad-ass Boss monster low-man style is just the best. It could also be a lot more challenging, because with low-man crews there would be less room for error. There is nothing too epic imho about zerging a Boss or throwing death-weakened people at it (no matter how many people die) until you finally manage to kill it.

So I say yes to challenging low-man content. My favorite PvE content in FFXI was CoP missions (pre-nerf). And I enjoyed the PvE endgame content that came from Limbus onward the most. I absolutely hated Dynamis and Kings. OW camping wars and huge unruley zerg-a-thons are horrible concepts. I was fairly OK with Sky and Sea, but that was mostly only when we went low man. Nothing like beating Byakko with 8 people!!

Not to mention other concepts that come from large-scale content like carrying unskilled freeloaders through events, the chaos of dealing with larger groups, fairweather LS mates that get their loot and run, ninja lotters, keeping up with drop distribution, drama, inability to function due to people not showing up to a scheduled event, and of course collision mechanics, the feeling of being a faceless cog in the machine because your actions are insignificant in the chaos of a large zerg. All of these concepts can either be eliminated or greatly reduced with low-man content.

This is not to say I dont think there should be any larger scale content, but I would rather it be limited. I liked the occasional Campaign. Overall, it is my opinion Large-scale content only "looks" more epic due to numbers, but in my experience feels pretty weak for the reasons previously listed.