I've had one of those - came as a sample and I promptly returned it.
The fans in that are nothing compared to the SM. Fans are completely unnecessary with SSDs. Should be find with non 15K drives too.
WDC does not have any 15K products. You are thinking of Seagate's Saavio series of 2.5" disks. Fastest (mechanical) i/o. They sound neat too. Speaking of sound I miss the sound of all those drives working and will be building a synthesizer module which will take drive activity (SGPIO) directly from the host and produce a click of variable intensity to simulate actuator movement.
The nice thing about the SM is it uses a true SAS connector so you have just cables going to it - a single four pin Molex and SAS 4X. Mine shipped with a SAS by SATA (has four SATA lines) but I run straight SAS so I had to order another cable.
The other design has SATA connectors you need a MINISAS to SATA fanout cable. Some of these cables can cost half as much as the mobile rack which is a rip off. I guess you can make your own if you have the time.
