Is it worth getting a iPad 2 if you have a iPad 1?

No. It is not

There are several threads on the Forum discussing the relative merits of the iPad1 and iPad2, including comparisons from Members who have both - or who have upgraded. You'll be able to see their conclusions. It depends too on the apps you're considered using.

Tim

There are some (Few) apps out there that can use the Dual Core CPU and the improved video. WingX with the Synthetic Vision add on runs much better on a Ipad 2 then on a Ipad1. But unless you are a pilot (real pilot not a sim pilot) and willing to pay the $200.00 for the app you should be fine with a Ipad1