I mostly read Reddit while not logged in, so I've never seen any latency. I guess it's mostly because of authentication/personalized content stuff, which should be easy to fix, by doing less of them or lazy loading.
In contrast, every page load by a logged-in user requires unique database queries for things like vote status on submissions and comments.
Their shadowbanning is the worst, I have an 8 year old account and I was shaddowbanned countless time, I was finally un-shadowbanned after years of whining about it.
I have a feeling Spez will get this right. Lets see.