Some friends and I ran T3 Reckoning last night with the Revelry grenade buff when the modifiers were Prism and Grenadier - the incredible grenade recharge rate turned out to be a lot of fun. It felt like a Mayhem Strike. Your grenades come back almost instantaneously - you don't even need to fire your weapon in the first encounter (and most of the bridge).

After a couple of runs we realized it was a golden opportunity to do the "The Old-Fashioned Way" triumph for not using any supers on the bridge - did it first try. Those modifiers are coming back on Monday, so just spam grenades, healing grenades, and healing rifts while focusing fire/grenades on the big guys (and make sure you don't use a super near the end of the first encounter).