I think you would be happy with it.
It is the only AIO I've tested that I will continue to use. I consider it an AIO, not CLC because it has a fill plug and components / hoses can be changed. I don't think pump is powerful enough to expand system with GPU block, but is plenty powerful enough as is. I need to try higher performance fans on it to see what temps do. My guess is they will drop considerably, but at the expense of more noise. As it is be quiet!, quiet is key word here.

be quiet!'s focus is on very quiet operation with super low temps taking back seat. It is not uncommon for their coolers to be 1-2c warmer than others, but they are quieter. Better looking too!
It cools similar to D15 at similar noise levels under normal loads.
http://hexus.net/tech/reviews/cooling/97741-quiet-silent-loop-240mm/?page=2
The above is with D15S .. temps will be 2-3c lower with 2nd fan & a couble dB louder.
I had TRUE Spirit 140 rev.A on before Silent Loop, also R1 Universl w/TY-147A fans and PH-TC14PE w/ new PH-F140HP_II fans on before that in this series of tests. I always run testing and use system for several weeks for a good 'real world use' feel of product. All performed similar. TRUE Spirit 140 rev.A is surprising good for it's size.

I did not use D15 because it blocks my PCIe socket, but R1 and PH-TC14PE have same performance as D15 .. at most 2c difference, and that is because D15 has 2-300rpm faster fans. Same performance at same rpm.
I have other coolers I need to test, but like Silent Loop 280 so well I don't want to change take it off just yet.
What EK did you have?