Most cheap OBD 2 readers are much the same in the way they work. I've used a £20 job off ebay for many years with no problem what so ever. They are limited to engine only faults but that's all I use anyway. I also use a bluetooth thingy that sends live data to my Android phone which is very useful too.
On another note, I bought one of these a few months back, works well with a laptop or iPhone. If you have (Very) basic network skills (Set a static IP adress, netmask and gateway) you will get it to work in no time.
Some cars works well, others don't. Some software for a computer comes with the reader, but it is certainly pirated, FYI.