One of the first metamagic feats I created in my campaign was "Expand Spell", which is basically like widen spell except it doubled area (for spells which state an area in 10ft cubes, for instance) or adds 50% to radius of spells with a circular area. I rated it at +1, because I saw it as being functionally equivalent to Enlarge Spell, and basically would only be useful on large battlefields or for clearing out more mooks, which is fine with me.
I was astonished to see "Widen" appear with a +3 rating. How on earth did they consider a slightly bigger fireball radius being as effective as a fireball which was guaranteed to do 60 damage? No contest!
I give the Widen Spell as written a "1", because they priced it right out of the market. At only a +1 level adjustment I'd rate it "5" - useful, neither a must have or must miss, just plain useful and might or might not be taken by any arcanist.
Cheers