I'm very impressed with my Iomega 1TB - it does create a bit of vibration on the desk (I have it behind my laptop) and the fan is audible - but I have already become used to it. I have mine on it's side with the blue light facing the wall so it doesn't bother me.
Re: above - if indeed these units to contain Seagate drives - I am much happier... I have had incredibly good luck with Seagates and have never lost data (quite the opposite with WD- drives)
I was sitting back yesterday and thinking about the pricing of these 1TB HDD Enclosures - for the price - it is cheaper to buy them and rip out the 2 500GB drives as opposed to purchasing 2 new 500GB SATA drives! What a deal!