The only problem I have with the Chromium packs is the unpredictability of it. If there's a certain character I'm trying to farm that's only available there, I have no reliable means of doing so. I spend my $30 and hope that it wasn't a waste.
If there was a way to spend extra crystals in order to guarantee drops for a certain character, I would be all over that. Something like 50-100 extra crystals to ensure you get at least 12 shards but with a 20-25% chance to drop the full character instead. That way, I'm technically paying all that money for the shards I want and then getting seven other sets of shards as a bonus, which may or may not include additional shards for my desired toon.