Are you sure your machine has the required specs for SQL Server 2005? I run the developer edition, which is obviously the Enterprise Edition w/ developer licensing, and I absolute love the new management studio. For starters, the new Visual Studio like design makes developing and performing Admin across all SQL modules obviously so much easier. I can have a connection open to the Database Engine, SSAS, SSRS and SSIS at the same time with no latency. My machine is an early 2008 HP laptop with a 2.5Ghz core 2 duo and 4 GB of 800Mhz RAM, so maybe I'm just more well equipped but even when running Vista I was zipping along at a more than fast enough clip. I am runing Windows 7 Professional and see some performance gain. It's really noticable at times, like when firing up often used apps.
As for teh number of clicks, I'm not sure I follow? I fire up SSMS and click once to connect (as you have to with EM) to the Database Engine, one click to open security and another for logins? Really not a lot of difference. The databases are inside of "databases" folder but that just makes sense and keeps the console organized. The solution explorer, and all other explorer windows are a God send.
I don't know anyone, besides you 😉 that doesn't think SQL 2005 management studio is light years ahead of the 2000 UI.
Having query analyzer there, with tons of MDX and troubleshooting tools at your fingertips, as well as Admin tools is awesome. In the long run, the old EM required me anyway, many more clicks and really click count is not a good measure. When you click say 5 times, right in the same area of the screen w/o bringing up new windows and having to reoriant and now switch between windows (if you use SQL for more than one thing you end up with several windows on your task back and lot's for switching back and forth. I have said so long to that old school UI and love the console.