Serum just released about a week ago I love it! I highly encourage trying the demo from Xfer. I made some factory presets for this beast and wanted to share a few of them starting with this particular "hard" bass sound called "FuckButtons". If you know the band then you get the idea.
Here is an Ableton Live 8.4.2 project file containing a Simpler instrument rack with macros to get an idea of these harder bass sounds you can conjure with Serum. Any version equal to or above 8.4.2 should open this project, no problem. If you don't have Ableton Live you can find the audio sample located in the "Samples" folder within the project file. The recorded sample audio is 16 bars demonstrating the non-repetitive rotation of subtle harmonic content in this patch. Long drone notes seems a little where it shines but doesn't appear to be limited to.
There are three example tracks set up each with a short midi clip for quick demo.
There is an additional chip-tune like effect added called "stutter-arp"on example 2.
If you like them then you can easily add these to your library by clicking the save button on the upper right corner of the instrument rack. There will be more soon!