I don't suppose anyone knows if EAC adds the correct tags to FLAC for the X10 ?
I don't know EAC because I use Linux, but I expect it puts data in the right tags. The question is whether the data is correct. My rip process pulls data from freedb.org (same as the X10) but the data is occasionally incorrect or missing, and sometimes for multiple disc albums it varies the formatting between discs.
That is especially a pain if the album names don't match because you'll end up with a separate album for each variant of the name. For example freedb might entitle the first disc in an album as "blah (disc1)" but might do the second as "blah - CD2". These both need to be just "blah" for them to combine as one album. So some manual editing may be necessary.
Tags do not need to reflect any file naming convention or directory/folder structure you might use to organise your ripped media. The X10 and other devices rely purely on tagging data.
The other pain is album art. This needs to be attached into the file but you really need to manually check this and perhaps supply your own. I have a low level of confidence in automated tools getting correct artwork. I use a combination of "albumart.org", Amazon and Google to obtain my album art. You may also find that larger images fail to attach (as well as waste space). I've found that keeping to 300x300 pixels or smaller JPEG file works ok.
If you want a really good tag editor that does album art also, I recommend EasyTag. It's free and available for both Linux and Windows (I have no experience of the windows version).
I rip my media on the computer so I am in control. I then upload onto the x10 and I have the x10's media area shared so that other computers can access it. My wife uses that share to access the library in iTunes (it plays the music located on the X10 on her PC, or syncs it with her iPod Shuffle). She also has a button on her web browser which brings up the X10 web interface and she can use this to control what the X10 plays.
I'm rambling on a bit - sorry, I hope it helps
PS. I also understand custom tags for iTunes so if this info is of use just ask