MSD yay or nay

Depends on your ultimate needs and/or goals. Some of the capabilites/equipment available with MSD are very useful or even necessary for some builds; ie retard units, rev limiters, and the like. For most street builds I still like the Chrysler electronics.
Not a fan of the RTR stuff or the (sole source) availability of service parts.
And the MSD knockoffs are another issue entirely!
It's kinda like asking if Holley or Carter/Edelbrock is the best carburetor- depends what you're after and how big a can of worms you want to open...