Unfortunately, it really is that good--I've been on the receiving end of a riptide throwing a large blast on a squad of 20 daemonettes that had just Deep Striked (Deep Struck?) in and hitting all of them--ow. Do bear in mind that the model that uses Interceptor can't use that weapon in their next shooting phase, but apart from that, it's a quite powerful rule. They even get to shoot before you have the chance to run and spread out (though the rumors for 7th edition say that moving and running will both be part of the movement phase, so that might change in the near future).
What sphinx of plascrete and adamantium bashed open their skulls and ate up their brains and imagination? Imperator! Imperator!