The guys and girls of Propellerhead worked hard to solve the performance issues of Reason. Although the focus was on VST performance Reason 10.3 in general now runs better and smoother than ever.
Now that we’ve had a month of beta testing I can also say for certain that even if you don’t use VST plugins, you’ll see performance improvements using Rack Extensions and internal devices too. As an example, the Reason 10 demo songs run 10-50% better on our testing machines using a buffer size of 512 samples.Mattias Häggström Gerdt (Reason Product Manager)
I am working on an album at the moment using Reason with lots of guitars (of course), amp sims and saturation devices. I started working on the album in Reason 10.2 and had to switch too higher latency settings when the songs got more complicated. But now in 10.3 even the most complicated songs will run glitch free using the low 128 samples latency setting using my first generation Focusrite Scarlett 2i4 (USB2) on Mac OS Mojave. Amazing!
I am a very happy Reason user. Greetings from the Netherlands.