Are there any specific reason for you to install Sonoma?
Are there new features in Sonoma that you need or find tempting?
Anything not working well with Ventura?
If not, stay with Ventura.
I tried Sonoma on my mini for a few days a couple of times, and had several problems both times. I also found no really useful new features, animated wallpapers and new emojies I can do without, so I'm still on Ventura which is working very well for me. I also have a couple of, for me, crucial apps that are not yet supporting Sonoma.
I'm thinking in a few months time we'll be seeing a mature version of Sequoia that's been tested by a lot of people, and I'll be giving it a try then.
There is no reason to think that upgrading to Sonoma will have any effect on the speed of processing or workflow. A so-called clean install, on the other hand, where you erase the drive and install a fresh system, will often make a mac feel more responsive and fast. But that involves (or at least should involve) reinstalling all apps and extensions, reconfiguring all settings etc. Many, like me, do that once every few years, especially if jump upgrading across a couple of versions of macOS. Like moving house and setting things up from scratch. Can be a good thing, and give a nice, fresh feeling.