Acid splash is d6, has a less-resisted damage type, and will usually hit the same number of targets (it's rare to have more than two enemies in a 10x10 box). It also poses no friendly-fire risk.I want the 4e cantrip "scorching burst" back... heck make it d4s
10ft diameter 5ft radius is 4 squares make it save for none like all other cantrips... start it at 1d6 is my preference but like I said I bet people would use it at d4s
I sometimes take acid splash as a backup, but hardly ever use it. A d6 scorching burst would be in the same category for me. d4 would be a nonstarter.