I'm getting about 100MB/sec from 3.5" Samsungs, WDs and Seagates today - but you're right according to these 4 year old benchmarks: http://www.storagereview.com/western_digital_caviar_blue_1tb...

I guess the configuration I'm benchmarking with, and the type of load, which is basically streaming, but from a journaled-but-otherwise-standard ext4, slows me down a little. But the convenience and standardness of this setup is worth more to me than a factor of 2 in performance (that's not my bottleneck at the moment).