I have had these 2 pieces for a few months now, and though the convienience of the extra battery is great, the grief from the case is not.
First-the case in this short time has rubbed almost all of the rubber tip off of the joystick.
Second-the unit sits so tight at key level every time it rings I have to remove it more carefully than playing a game of 'Operation'. If I remove it normally the 'answer' button is pressed. Maybe I don't want to answer all calls.
Third- it has a tendancy to call people on it's own. You hang up and put the phone in the holster, and discover later that you called the person back and stayed on the line for 20 minutes.
I guess I'll go back to the stock battery for now. I realize the 3 points above all point to the same issue, but i'm not goint to start cutting out parts of the holster...it was a quick 'get to the market' design, and my decision to buy was the same.
Live & learn I guess.

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GO OILERS GO!!!!!!

sounds like you could use onlock, it will prevent the answers when you don't want, and other mispressed buttons - I use it all the time and would consider it a true must have ap.

I've been using both with a fair degree of success for about a month now. Only once have I called someone by accident. I did notice, though, that you are right about the rubber joystick nub - I just looked at it and it is indeed wearing down. Oh well!

It is true that you have to extract it carefully from the holster, though. I never answer the call prematurely, but many times the loose battery door flies off. I love the battery otherwise, but the door is really terrible. So far I've had pretty good luck with this setup, though.