I haven't seen any issues in the past about ppl running the Diablo for tuning. Hell the fastest hemis are all running the Diablo... Plus it's a cheaper option for guys wanting to run a stock PCM with a custom wiring harness.
If DSP would give complete control during an engine dyno, I'd be interested to say the least. DSP with truck transplant engines and transmission's = fail. The RFE545 transmission will be the first wink link to go.