Okay, but if you pedal faster it might load quicker
Seriously though here are some productivity gain examples:-
1) Make 1 compile, then modify something in the sketch source code, then make another compile. Hopefully, the re-compile is very fast and saves some time.
2) Use the "update variable" facility to test different values with the debugger, this avoids the need to re-compile and upload so often.
3) Of course, just having intellisense, means that most of us (non-experts) have to go hunting for reference material much less often which is a huge time saver.
4) The facility to inspect analogs, digitalpins, registers, expressions and sensor/variable values with the debugger saves me having to dig out old reference guides for the various bits of hardware that I use from time to time.
5) If you change sketchbook folder very often, or want to switch between arduino versions or if you edit your own custom hardware (boards.txt) files is the fact that the ide does not need to be re-started. The UI can auto detect and reload all cores and libs without even the need to close the current sketch.
6) Atmel Studio comes with VisualAssistX which not only gives great code explorers but also provides code re-factoring. This is a superb set of tools that allow us to easily (single click) re-structure the code of our projects.
All in all, I think we have some huge productivity gains with Atmel Studio but I agree it is nice to have an ide that opens really quickly.
Visual Studio 2012 opens really fast, I hope Atmel use the VS 2012 shell for the next major release of Atmel Studio. I really like Vs2012 and it works very well for Arduino development, you can see some images on the visual micro web site.
EDIT: here is a youtube example of Atmel starting in a relatively short time. Notice I ensure that the Atmel Start-up page and ASF explorer are closed. I don't use those windows very often and they slow start-up time. Win7 64bit i7/8gb. http://youtu.be/RQkOLCWEAcc