Finished the omnibus last night. Wow! Loved it! The ending of Wool 5 was perfect in that it left the obvious opening for continuation but still wrapped things up enough to feel like an actual stopping point.
Can't wait for the next one! Wool 6 will actually not be Wool 6 but the start of a new Wool-based series. There's more info on his blog that Jerry linked to above, but don't go digging too much if you haven't read all of this one yet.