The 2001 Lotus and my M5 are pretty equivalent in straight line acceleration, which makes sense based on the S2 C&D numbers and known 0-60 times for the Esprit.
Dinan has done a wonderful job on their mods. They provide very clean power that is delivered instantaneously (as opposed to forced air induction mods).
The Dinan M5 is definitely faster in a straight line compared to the 1999 F355 Spider I used to own.