Silver Bell is - and always has been, for me at any rate - Patty Griffin's best album. She continues to release strong albums, but on Silver Bell she was at the height of her song-writing powers. On later albums she became a little over-produced IMO.
Like many fans I've had the original Silver Bell for years but whether you're in the same boat or whether this is completely new, it's an essential purchase for any fan. First of all the quality is excellent (although the levels vary) but more importantly this official version has two tracks not touted for the original release (at least not at the point the project was halted) and not on the bootleg (though just how official that track listing was is open to question): Fragile and So Long. Both are good but Fragile is just a wonderful addition. Unfortunately, two tracks have also been dropped; Standing can be found almost unchanged on Impossible Dream but the other track, Making Pies, would now seem to be completely lost, unless you have the bootleg. Both replacement tracks, though, are stronger than that song.
Thankfully, the producers haven't seen the need to go overboard on the re-mixing. There are changes, but they're subtle, so what you get is pretty much what Patty produced back in 1999/2000, a snapshot of a great artist who was less polished than today but perhaps more creative.