Enthalpy is nicer (in my opinion), as it's $400+dyno-hook up fee and you get your ECU AND your dyno-tuning. Re-tune are $150 + dyno hook up.
They are very adjustable. 600whp VVL SR tuned the other day via enthalpy. Mine was 440whp at 15psi. (Broke my boost controller day before so couldn't turn to 30psi). He tunse for E85, race gas, etc. etc. No problem
If you have any questions at all just message me, or add me on facebook (facebook.com/ajdrift) and I'll be happy to answer any questions you have or put you in touch with martin (RS-Enthalpy owner).