would a standard neo geo cd top loading system be okay for playing shmups, and others like NAM 1975, Magician Lord, Metal Slug 2 etc? would loading wait times be reasonable?
or would the cdz be a better option (bearing in mind they cost twice the price of the normal cd version)
The Toploader is fine. Most shooters have really reasonable loading times. Everything under 100 Mega, like NAM '75, Magician Lord, Last Resort, Viewpoint etc only loads once at the beginning anyway. Pulstar and Metal Slug 2 load a bit more often, but I still think it's not reason enough to warrant the extra cost of the CDZ. It's mostly the Vs Fighting games that get hurt badly by load times.
I'd get a normal top-loader, it lasts longer. Loading times for most shmups are ok. The CDZ's CD-Rom mount is apparently not very durable; I've heard many stories about broken drives.
Yeah, for shooters, it doesn't really matter. Save your money and go for the normal top-loading NGCD. CDZ basically halves load times for like 1.3 the price (not double, unless you plan on buying the first system you see).
