I never could get lined up right with the Deuce. The cover seemed to tame for what I was expecting.
I got a new in box Deuce a little less than a year ago as a 'smooth' medium-heavy oil ball. The cover never matched up with my house shot and it seemed to go longer than I wanted. After trying a couple of cover tweeks I gave up on it. 2 months later I replaced it with a Vertigo and I'll never look back.
For some reason Storm only used the SFA (modified Accutread) on the Vertigo and the Trifecta - both of these balls are about as predictable as you can get.
The whole matching covers, cores, and conditions to a particular shot is a voodoo science to me. Over the past 5 years I have liked certain Accutread, Monsoon, SFA, and Reactor balls and in the same breath I've hated balls with the same coverstocks.
To answer your question Lefty I replaced my Deuce with a Vertigo and I am happy with that change. I have never thrown a Diablo but from what I've seen I would expect it to be a good Deuce replacement. Also, from all indications a Dark Thunder would also fit in that space. If you are looking for a solid with a stronger core I would expect Storm to release a solid reactive Agent within the next couple of months.