I have the old Antec H2O 920 and its already million times better than the Thermalright AXP-140 which was already far from a bad low profile cooler. But overclocking made its job and it simply wasn't up to the task. Antec 920 can keep 4,2GHz Core i7 920 below 80°C with custom Noiseblocker fans at lowest speed (tested with AgentGod's IntelBurnTest using 20 passes and High memory setting). In normal conditions, it never goes past 65°C (like while playing Skyrim for hours). Meaning it's pretty much dead silent, yet it can keep heavily overclocked CPU properly cooled. I don't think i could achieve this even with the most high end tower coolers, not without setting fans to ridiculous (loud) speeds. At least not in my small case that is.
Sure it's better to have the latest gen coolers but then again old generations seem to do their job just as good.
RejZoR's Little Secrets @ rejzor dot tk