The MSD is kind of a hybrid, it uses a trigger system like a Duraspark but has the advance mechanism of a Delco.
Advantages to a MSD are curve adjustability and improved bearing and bushing designs in the housing as well as billet housing availability. The MSD distributors I have are not double pinned but mine are 10+ years old.
Both distributors can work with various MSD boxes and both can be converted to big or small caps.
The Duraspark is a pretty good distributor but lacks some of the modern gimmiks that the MSD can give. Curving and adjusting advance limits can be a little trickier but once it is set you are good to go. I have a 30+ year old car with the original Duraspark distributor and box that hasnt missed a beat.
Sometimes the duraspark box can be suspect but as I stated a number of aftermarket (mallory, MSD etc) boxes can be made to work with them.
I am personally running a Duraspark in my Pantera simply because I had one already.
Maybe your friends could expand more on why they are favoring one over the other?
