I was very sceptical about ordering this because of the mixed reviews. However, for £3.20 I figured it was worth a go.
Some people have had problems getting it to fit properly into the ipad port. I had this too -it just wouldn't fix in properly or work. To try getting it working, I used a ruler to gently push the problem connector on the reader back and forth to loosen it. This did the trick and how it fits into the ipad just fine.
Another slightly confusing thing is the little switch on the right hand side. This needs to be in the USB position for the reader to read the USB and start-up the software. After that it took around 5 seconds to read the SD card and start up the software. It basically creates a new folder in your Pictures and downloads them into it -fantastic! Worth the wait and hassle as it transferred a few hundred photos without a problem from my SD card.
About half way through the transfer I got a message "Item not compatible with this ipad". The transfer continued in the background and I simply clicked OK and everything continued just fine.
For £3.20 I would recommend giving this a go -there are obviously some manufacturing issues, but if you get one that works it's great.