Highly recommend this data logger shield for Arduino. I bought tree of them so far. Performance wise it will obviously take some additional time to check for battery life expectancy, but so far so good. The card sleep functionality in my opinion is a major advantage compared to other data logger shields on the market.
I believe though the card would benefit from changing the micro SD card slot for an ordinary SD card slot. It would be a great advantage, especially when changing cards during field working conditions. In my case I find the micro SD card easy to drop and the tiny card case locking mechanism easy to accidentally dent or bend when replacing cards (and the situation will probably aggravate with more usage). There is plenty of area left on the shield and using some of the (empty) prototyping area how many potential users would really miss that lost area?
The developer mentions having used the card with a 2GB card size. I have tried with Sandisk 16GB and it works just fine.
The shield documentation uploaded to Git hub have the benefit of (occasionally) being less informative and perhaps somewhere even incorrect , so it encourage you to read it in more detail before you start messing around with the code.
I had some questions, requests and remarks and contacted the developer. He was most accommodating and helpful. Responded quickly.
This shield worked perfectly for our battery operated Arduino loggers. We are using a number of these shields at an edge of farm field study monitoring and recording water depth from a pressure transducers.