There is no Hypertech available for them and prolly won't be for a while. Dodge doesn't want to let loose of the code for the PCM which keeps them a long ways from anything serious. They can't even get colder plugs for spray yet. I actually kinda feel sorry for them.

15.5 is slow for a RCSB HEMI. They should be low 15's or even into the 14's. If it was brand new, then I could see it as they like to cripple them when they are new and from what they say they loosen up a good bit with some miles on them.