No first-hand experience the Xigmatek or Sunbeam Core Contact. I was not convinced about the Sunbeam in comparison to the OCZ Vend 2 and the TRU120 and TRU120E, or even in comparison the Ultima 90.
With the Noctua and a different fan or fan-placement, I think you can trump the TRUE by about 4C-degrees. The IFX-14 would also trump the TRUE with an appropriate fan deployment. The way most people might use it, the difference could be significant.
However, with these new 45nm cores, unless you're pushing your VCORE voltage above 1.35V and going to extreme FSB levels, the focus today should shift to chipset cooling or chipset cooling solutions -- both commercial and DIY.
I've tentatively chosen to sideline my Noctua NH-U12P for last year's Ultima 90. The Ultima was actually a second-place to the TRUE, or maybe even third-place or close tie with the Sunbeam Tuniq.
Here -- and I repeat "tentatively" -- I chose this route for a ducting approach that may allow me to eliminate the chipset fan and get better temperatures there. If I want to replace the Ultima with the Noctua again, the backplate assemblies are interchangeable, and the two topside brackets and screws fitting the backplates (either one) can be swapped for either cooler.
Put another way, my E8600 is OC'd to 4.0 with 4.1 Ghz voltage settings. IntelBurnTest won't push the cores beyond 65C with room ambient of 78F. I think that's pretty good, even if the Idle-to-Load spread in temperatures is wider than it would be for the Noctua.
But . . . . I can change my mind . . . . . Innovative Cooling sent me a free, $20, 24-carat tube of Diamond thermal paste.