I just upgraded to 7.5.9 and it has the same issue. In general they are zippingly fast. The *only* thing it has an issue is with that initial post.
If the whole system was slow, I could understand the RAM issues. And I did have them go up from 4 gig to 5 gig. Plus I have another 3 gig virtual. But I just can't see it's a RAM issue. Everything is fast everywhere. Everything in all my aspects of my site are fast.
The ONLY thing that is delaying is the initial post, and that's a 20-30 second delay. That doesn't seem like RAM. That seems like something else is wrong. Subsequent posts are fast. It goes from 20-30 seconds to one second and consistently stays at one second after that. We're not talking about a few seconds of swapping time slow. We're talking about something-going-wrong slow.
I've been a developer for over 20 years and I just resist throwing hardware at an issue, when I can't see it as a hardware issue.
On the smarty, didn't that happen as a normal part of this upgrade?