Not Samsungs so I don't know if the make makes a difference and I haven't tested them in a while, but my Intels benchmark the same whether used as OS or data disks.
Generally speaking SSDs have very fast access times compared to electro-mechanical drives which ought to pay off on a drive containing lots of samples, assuming the sample files are small.
Benchmarking doesn't always relate to real world performance, and different test software can give very different results. Even if SSDs didn't beat HDDs for speed there'd still be an argument for using them in DAWS - they're silent and use very little power, which means a lower-rated psu can be used (including finless ones) which in turn means less noise emitted by the PC.