i was considering it as well, i read the anandtech review with the great performance of this cooler so i might go for it.
i havent made any measurements yet, but just by looking, i think the big popular blocks wouldnt fit in my case (Tuniq, TR-120-ex, CNPS9700 etc') plus they are expensive! (around 100$ after tax where i live). so this looks to me like a sure thing.
one question though: i have modded my case, and put 2x120mm fans on the lower half of the side panel, and i have MASSIVE air flow which goes out of the FRONT of my case (i opened the 5" slot above my CD-ROM). Would i be able to place the ultima-90 so that the fan blows the air towards the front of my case so the hot air would be pushed out by the case's air flow?
(i know it sounds weird but it works! my E6550 idles at 27c with stock intel cooler and if i turn them off, it idles at 41c! load during Oblivion is around 56c. Plus, these babies are just above my X1950Pro so it gets cooled as well. only down side to it is that i cant hold an O/Ced load at normal temps since it still is an Intel heatsink and it doesnt dissipate the hot air fast enough and thats why i want an aftermarket cooler)