They both do the job, The MD is just a better tuning tool.
Remember tuning is usually why you put your car on a dyno to begin with.
People just like that higher number though, and we'll never get away from that.
Kinda like Lapeers' trap speeds.
(local joke)
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1988 Mustang GT
11.8 @ 123 (7/14/01)
1992 BadAzz Wrangler
1993 Explorer