Firstly, thanks for the objective review. Members need a heads up.
Be aware that since Sept. 2006 there have been negative remarks and reviews of Seidio and/or some Seidio products [e.g. the black rubberized cases that first came out]. So people are not afraid to speak up and negative reviews are allowed [and welcomed].
On both extended batteries I did tests, quite extensive. The "medium" extended battery worked very well compared to the OEM battery. And of course, the 2400 battery lasts over a week without charging.
My speaker grills on both covers [the medium and the 2400] have both held up well. In fact, the covers are of far better quality than the OEM cover.
Back in October 2006 I purchased a clear case [the hard plastic one]. I noted that the construction of it appeared poorer than other Seidio cases. I disliked it so much that after one day's use I tossed it into my cell phone drawer.
Conclusion: Maybe you got a bad battery. And the case... I dunno about that, but I did not like the Seidio clear case that I got.
As to Seidio not getting back to you, other members have complained too.
Seidio used to have an employee, I think his name was David, who was a member here. He used to respond to all members who had a complaint and he always made an attempt to fix the problems. At times he also apologized for other's poor customer service [that is, other Seidio employees]. He was a damn good employee.
I have not seen him around in months. So maybe he left Seidio.
From what I can conclude from posts over time, it seems Seidio is having problems in the customer service department. But I still believe in their products.
Hopefully, they will get their act together because they deserve our business. They were the first to come out with cases, batteries and headset adapters specifically for the Pearl, so I'd hate to see them lose customers because of poor customer service.