Another thing to look out for is the design of the card reader ... I will explain: I have a camera which uses compact flash cards. Now these things have two rows of holes into which go corresponding pins which are at the bottom of the compact flash card reader socket - just like in the camera. However, unless the CF socket is long enough to ensure that the card is properly aligned before the final "shove", it is very easy to get the holes in the card and the pins in the reader socket misaligned. Result - bent pins in the card reader socket which are either difficult or impossible to straighten out.
I have to say that this is not normally a problem in the "stand alone" card readers but the one in my PC is a different matter - the CF socket which guides the card onto the pins is only around 15mm in length which means very little stability as the card goes in - it can wobble from side to side very easily as it goes in and now ..... it is broken! So ... I am left to using my USB 2 card reader in a USB socket - no worries but more than a bit annoyed that my built in CF reader is unusable now. (Hope all of this makes sense)!
Alan