I also asked myself at the beginning: Is it really necessary that thing? The answer: No! Absolutely not, but if you use the Circle Pad, you definitely more fun. It's getting used to at the beginning, but you get used to it very quickly, mainly because the thing is very smooth in your hand.
In addition to the three new buttons (or slide pad) is an additional "R key" to, because one would not achieve the original key so. In addition, it is very nice that the Circle Pad Pro is not applied to right-handed, the control is easy to switch to left-handed.
Disadvantages are stupid little things, such as that one can achieve neither the card slot, yet the stylus. This should have been better able to solve! Due to this fact, one is compelled often the 3DS from the thing to take out, while of gaming ...
But at least keeps the battery (is supplied) countless hours making not quite as bad replacement.
Conclusion: A very good idea, unfortunately, there are still just three games in which the Circle Pad Pro can be applied. But for these Games is worth the purchase of this fine, little extras. I wish mri definitely more games for this add-on in the near future.