If you can use the iPad 2, then the display should look sharper than the iPad 2 because the mini has the same number of pixels in an area half the size. Also with no "sandwiched" double glass in front, the image should be clearer and brighter, more easy to read outdoors than the iPad 2.
The same processor powering a smaller device should give it better performance than the iPad 2, of course cannot compare with the 4th gen iPad. Just imagine XGA resolution on a 8" screen, not quite retina display but quite close. In fact retina display is relative. Hold it further away, it should look retina.
The key strength of the mini is in its handiness, its thinness and its light weight, lighter and thinner than the Nexus 7 even with the larger screen. The 4th Gen iPad may be a more powerful device but too big to lug around everywhere for some people. The mini is small enough to put into most lady handbags.
Finally, you can do everything you do now with the old iPad, meaning whatever application or page written for the older iPad which you can view full screen, you will also see it full screen on the mini. I believe on the 4th Gen iPad, unless the application is upgraded to be compatible with the higher resolution, you will view it only on a small part of the screen. Have you open applications meant only for the iPhone on the iPad? Exactly the same thing.
The proof of the pudding is in the eating. Pick up a sample and try it.
I almost forget. If you can catch hold of 4G/LTE version, not launched yet in Singapore, your cellular speed will be almost as fast as your Wifi speed.