OWC Mercury Helios TB2

I just received my Helios TB 2 today and the installation was quick and simple. I also installed a eSata raid card as well. I've been running it for most of the day and it seams to be very stable. My cards perform just as they did in my old Mac Pro. The craftsmanship on this unit is very good. It has 2 pci-e slots not including the one for the thunderbolt card. One of slots is a an 8x length and the other is 4x both running at 4x speed. The only down side to this unit is that the fan is noisy but, I am replacing it with this unit http://ift.tt/1qXxCbZ. It will be very easy to replace. It is the only thing you hear in my control room. I had to do the same thing with my Avid HD I/O and it's very quit now as well. I don't know why these company's won't invest a few dollars more for a quieter fan especially since they know what we buy them for. The new Mac pro has defiantly set a new standard for quiet! I can literally here a pin drop. I just thought I'd give my experience in case other are wondering how this unit stacks up.