I'm happy to say that I've never stopped playing and enjoying my ELO albums, so there was no real need for me to get excited about this reissue. But I bought it anyway because I didn't have a CD edition, and because my LPs are a mid-price 1980s reissue in a one-piece sleeve, not the beautiful gatefold original, and I'm well pleased.
As other here have remarked, there are two ways to view this, and they depend on whether or not you already have a playable copy. If you do, you have to want the little book and the model spaceship - which are both nicely done - because the remastered sound is nothing remarkable. Not that it's bad, just not a reason in itself for replacing the copy you already have. The three extra tracks are the sort you will play once and once only - two are mere curiosities and 'Latitude 88 North', while it may have been written at the same time as the album songs, was recorded more than 20 years later (Lynne explains this in his notes) and sounds like a Traveling Wilburys effort.
So that deals with the reissue part. What's left is one of the great musical creations of any period. Ignore the words - Lynne never had any great pretensions to be a lyricist - and soak up those fabulous melodies, harmonies, cadences and layers and layers of sound. It's (still) fashionable to disparage 'Concerto for a Rainy Day' but I love it - especially the long instrumental introduction and, most of all, 'Big Wheels'. As Steve says below, it's wonderfully constructed - although you might find a certain irony in using so many people to perform a song about loneliness. It's up there with Siegfried's funeral scene in 'Gotterdammerung' for dramatic deployment of gorgeous, juicy chords - although it is, of course, pure coincidence that the discarded section from Wild West Hero contains a reference to falling into the fire!