Its weird cause the other menu's are still being served from the CDN unless it had to go to the server to fetch.. then it should have hit varnish cache... but once you been to the menu once it will cache it on your browser so it will be quick to click on the same menu again.
If your logged in there is no caching since cookies are stored for authentication.
I run a ubuntu server too, but not yet with SSD.
Would you say that it's worth it to change to SSD?
Internetspeed is so much dependend on other things too... not just the harddisk type...
I plan to have SSD as well. Anything else could speed up? memory? CPU?