The major gain in peformance with the SB-e is the frequency, not so much the latency. So if you have ram that you can get solid at 2400MHz or higher

(8Pack and 2500MHz for example) then your bandwidth and performance will be right up there.
Now the kicker.
As a normal Joe, using their system for 24/7 stuff gaming and the like you are hardly going to notice the difference between your system running 1600 and 2133. Yeah you will shave a couple of seconds of how long it takes a file to be archived or extracted, or a 15 second gain on how long a render takes - but when the task is measured in tens of minutes those kinds of quicker become rather irrelevant. For a bencher, like the idiot I am, yes it is huge. I get all of 120 extra points in one benchmark, and 600 more in Vantage11 on my CPU score. And those margins are the difference between top 30 and top 100.
From the bragging rights and sheer hell of it, oh man it makes a difference.

But that is me being brutally honest about it. Is it worth the money, that depends on what you want. For me it is, even if I was not benching I like to have cool toys. But that is just me.