Ubuntu 19.10 is unusual for an October Ubuntu release in that I would call it a must-have upgrade. While it retains some of the experimental elements Ubuntu’s fall releases have always been known for, the speed boosts to GNOME alone make this release well worth your time. If you prefer to stick with more stable releases, most of what’s new in 19.10 will eventually be backported to 19.04 and possibly even the last LTS release, 18.04.
Still, unless you’re unflinchingly committed to the stability of LTS releases, I see no reason not to upgrade. As I said at the start, Ubuntu 19.10 is quite possibly the best release of Ubuntu Canonical has ever delivered. It’s well worth upgrading if you’re already an Ubuntu user, and it’s well worth trying even if you’re not.
The speed improvements to GNOME are incredibly enticing. I’m a Mint/Cinnamon user, but this is definitely intriguing me.