The drum kits in SRX-01 (Dynamic Drums) are thick . They have a boxy, compressed attack that sits perfectly under a dusty sample loop. Furthermore, the Electric Pianos (Rhodes/Wurlitzer) in SRX-03 have a "gritty bell tone" that modern EP VSTs lack.
If you are dipping your toes in for the first time, do not buy the whole bundle. Start with . It is arguably the most valuable sample library Roland ever created. Between the "Jump" brass, the Juno-106 waveforms, and the TB-303 acid samples, you will find a use for it in every single project.
Here is why that is a good thing:
For producers of that era, buying an SRX board was a significant investment, often costing hundreds of dollars per card. Today, the VST versions offer these same libraries for a fraction of the price, with none of the hardware maintenance issues.