I've been playing with the latest 2.5 build (trunk) and have noticed that the admin area seems remarkably slow in comparison to an installation of 2.3 on exactly the same host, using exactly the same data.
Whilst 2.3 snapped between pages at speeds almost comparable to localhost, 2.5 seems to spend a lot of time negotiating something or other. Firefox flicks between "Waiting for XXX..." and "Transferring data from XXX" numerous times for each page load, but I can't work out what it's actually doing.
Just wondering if anyone else has observed this.