How important is this thing for Resident Evil Revelations?

Amazon is trying to steal your money, Oniyide.

I've fully completed it including getting all S ranks on all the Raid Mode stages without it.   But I hear it does help make it easier to move and shoot.  I am pickign mine up on Monday so I'll let you know how much of a difference it makes.

What he said.  You can set the controls a variety of ways.  One of them will definitely fit your needs.  I have a circle pad pro and it's easily the best configuration for me.  Really intuitive and comfortable.  I didn't have my CPP with me at work today and I started playing insane mode with the single circle pad.  Had no problems at all.  You have to remember that even on the Gamecube and PS3/360, the Resident Evil games were designed to play with one analog stick.  The CPP just adds the ability to use a better FPS/Gears style of control.

I also had no problems at all to complete Revelaitons (...) without the circle pad pro. That said, I did buy it later from Nintendo in order to play MGS3, and I don't see how I could have managed finishing that one without it (even with it the controls were quite horrible imo, I don't think I will be playing another MGS in the future between the controls and the cut scenes, but that may just be me).

Finally acquired mine.

For RE:R, I'm not really fond of it. But I suspect this is because I have already put 39 hours into the game without it.

I do plan to play MGS3 next so I'll be able to compare from the beginning with both methods.

played both games without it, MGS isnt that bad, that is if you are already used to playing the PSP MGS games, if your not, then you would probably want that CPP