Sent them both through a spectrum analyzer (primitive single-saw init patch, filter fully open) and the Hive spectrum seems to drop off a couple thousand Hz earlier than with Sylenth (for instance 16 kHz vs 20 kHz roughly). Maybe that is why I perceive Sylenth as brighter and edgier, others might say more digital.
https://app.box.com/s/vroe6ur2ki0ena56uaf4gba075hl4w89
On the other hand, with Hive the spectrum rolls off in a gentle curve from about 10 kHz on, whereas on Sylenth the spectrum often simply ends in a vertical drop higher up
However, I assume Hive's spectrum is more like that on hardware, right?
I don't know much about those things, but I found it interesting
