My most used applications are MicroB, Mediabox, Pygtkeditor, RSS Reader, MyTube, Emelfm2, Terminal, App Manager, PDF Reader, Tear, Leafpad, Vagalume, etc. I shut down the device every night and turn it on every morning. I probably use 75% of the above listed apps every day (opening & closing them more than once), and use an array of other apps, too (I boot from a 2gb sd card, and it is almost completely filled with apps!).

My device is always just as responsive as when I first boot it after closing everything down (namely the browser, it sucks down quite a bit of memory when open).

The only thing 'different' with my device is that I boot off an sd card and have a massive partition for swap (~400 mb).

But my device was always like that, even before I made the huge swap partition (the swap is for debian applications, mostly).