Let me see.. I come from Amarok. It lets me change all meta data on all marked files all in one go. I can mark all files and tell it to change artist for all tracks in one go, I can tell it to change album for all files in one go, I can have it run out on the net and collect track info based on the file names, song lengths, and analyze the files by using musicbrainz - all in all it does exactly what I expect from such a program. iTunes on the other hand is more of a hub for iBobs, and pretty much just that. As a music player it stinks, as a meta data editor it's just way too silly.
You power user comment is highly ironic.
For what it's worth, in iTunes, select a bunch of files, "get info" then you can change all of their metadata - album title, artist, year, etc.
Earlier on the thread, the "compilation" issue was mentioned; If you select a single file, on the "Info" tab, there's a checkbox for "part of a compilation". If you've selected multiple files look in the "Options" tab for "Part of a compilation". Yes, it's bad design that they're on different tabs if the files are selected differently. "Compilation" will group them all together as one album in your listing, and store them in a "Compilations" folder in its music storage area... if you look on the filesystem for that sort of thing.
If you're on Mac, there are a bunch of AppleScripts that people have written to do things like remove track numbers from filenames and shove those into the track number tag fields, etc. I wrote a simple AppleScript where you select a bunch of tracks, and it renumbers the tracks based on the selection 1 of 5, 2 of 5, 3 of 5, etc.
Does it have one of those nifty "automatically figure out what this song is" features? No. but I've seen a few secondary apps and such that do that.
I understand having legitimate complaints about iTunes. I've used it for years, and I personally like that it organizes and wraps a searchable database around my media files. I'm done with maintaining a filesystem heirarchy myself. And yes, the iDevice's display of some of this stuff is.. .awkward at best (put a compilation on an iDevce, then look at your "artists" listing -- it's a mess.) But complaining about lack of features that are actually there anyway is just silly.