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If you need the app storage space it is worth it. If you don't its not. If you don't need the space I don't even see the point.

You are forgetting about something. The ability to flash ROMs and do system wipes without ever again having to reinstall your apps.
As for the "is it worth the trouble", if you are running a Cyanogenmod ROM, it is no trouble at all. 4 screenpresses in rom manager and then tick an option in the application menu of the phone and viola, you are done.
Better chance of apps running slow if they are running off the sd.
I haven't seen that to be the case, though.
There doesn't seem to be much point in running a Class 6 card, since the Droid's hardware cannot transfer data any faster than a Class 2 card anyhow.
One of the folks over at Droid Forums ran some tests yesterday after I made this very statement, which seem to disprove the theory. The difference between the two was small, but more pronounced the more data was being moved.
[ROM] Bugless Beast V1.0 ESE81 - Page 152 - Droid Forum - Verizon Droid & the Motorola Droid Forum
are you running apps2sd?