Earlier this week I received the Seidio high capacity battery for my T-Mobile G1 phone. The battery easily provides double the life of the battery that ships with the G1, but I have decided that comes at too high of a price. With the battery the G1 seems to nearly double in size, it’s so much larger that the battery ships with a replacement back cover. It also makes the G1 so heavy that I find it uncomfortable to hold in my hand for any extended period of time, such as while reading through RSS feeds. So, basically my advice is to avoid the high capacity battery unless you are prepared to carry what feels like a brick.