Looking into possibly getting one for my own use as I currently have 4 BMWs (2x E36, E46 and E39)

Would be useful to have, All I want is something to just connect with the car, Read the codes and tell me what's wrong.

Would something like this be worth buying? Or is there other cheaper options?
http://www.ebay.co.uk/itm/Peake-Research-R5-FCX-3-U-1987-2005-BMW-Service-Reset-Fault-Scan-Tool-/261259319904?pt=UK_Diagnostic_Tools_Equipment&hash =item3cd444da60


I assume it works, By giving a numerical code that I then have to look up in the code chart?

Total novice with these, So any advice welcome!