EXTERNAL DRIVES : ARE THEY REALLY FAST?

1. When one goes for buying a external hard disk,how important is for him/her to give due importance to speed that is mentioned as spec....like 7200 rpm and 5400 rpm?Does it really matter in this case?

2. Well not much and as a matter of fact the difference is ZERO = NULL = NIL.The faster the hard drive ,the better : this generally stands true for the internal drives that remain connected to IDE/SATA.In most of the cases pertaining to external drives the interface of connectivity is none other then USB which is significantly slower equated to SATA/eSATA/IDE on any day.USB drives at the most support a transfer speed of 33-37 MB/s...and thats all...whether u connect a 5400 rpm or a 7200 rpm..