I save my shards for these events, but as I do more and more I've realised I haven't hit a worthwhile Legendary.  By worthwhile I mean one that would improve my TAG team, Arena, Doom Tower, or really any team apart from some Faction war teams.  This probably cpvers 12/14 legendary pulls, so the last 6 or 7 plus the extra

I'm wondering if (and this isn't new I've thought for a while) if RAID subgroup Legendaries much as we would, so the best are A listed, and you have the best probability to pull from this group of you're a spender, if not maybe a 20% chance  then the B group - good useful Legendaries, say a 50% chance to pull from this group, then the C group - the vault keepers, normally 30% chance  but when the extra event is on a much higher percentage to draw from Group C less from B and not much chance from A 

Or is it just my continued bad luck and some of you (non spenders) have got the top guys when you've done the +1 event