Ye Olde GM
An example? Alright. Let's use Axe Expertise for an example.Well, perhaps errata doesn't cover the full text of the Rules Compendium (though I'm pretty certain that all functional changes have been addressed this way), but I was under the impression that every rules element (feats, powers, races...) changed by Heroes of X had been included in an errata document. Do you have any example of an exception to this?
Better yet, let's get real specific here. I want to play an Avenger (which is not an Essentials character), and I want to take Axe Expertise (an Essentials feat) as one of my feats.
Axe Expertise is not listed anywhere in the errata, so there's no clear indication that it supersedes, replaces, or works in conjunction with any of the earlier edition feats or options that work similar to it. Naturally, we just make the assumption that it does. It seems logical, and its probably a safe assumption. Most of us might accept that, but its not guaranteed because there is no definitive source to give us an answer.
Let's further examine the scenario with a hypothetical. Let's say I'm the kind of person who decides for himself that I want to also take Weapon Expertise (Axe Group). In case anyone hasn't noticed, there is not a single reference in any Essentials products anywhere to content, materials, or rules that came prior to it. It doesn't mention Player's Handbooks, Dungeon Master's Guides, Monster Manuals, etc. Or I haven't found any, at least. I could reasonably argue that there is nothing to prevent me from doing so, unless the DM flat out decides not to allow it. Granted, it is well within the DMs right to reject the notion (and rightly so), but now we have a difference of opinions on what should and shouldn't be allowed because there is no clear, concise, and definitive answer for all of us. That is the confusion inherent in the Essentials line of products.
Try not to over-analyze the example because that's not the issue. We can discuss every instance of every example to find a reasonable solution for ourselves, obviously. The point is that we shouldn't need to, and that is where the Essentials line has failed for some of us. And for those who challenge that there really isn't any confusion out there, then whey do we keep seeing discussions like this one? The consensus of one's personal group or table does not necessarily reflect the greater community outside their circle.