In our testing results, the Scythe Mugen 5 does give something of a mixed set of results. Putting it as simply as I can though, while the noise levels are a little on the high side, the manner in which it controls the temperatures (which is arguably the more important factor of the two) is excellent.
At both stock and overclocked levels, the Scythe Mugen 5 provides some highly-impressive temperature results. Which, by air cooler standards, really makes it stand out as a quality product with a fantastic design! It does, however, come at the cost of some mildly (but not obnoxiously) noisy fans.
If it was a cooler I was going to use personally on a daily basis, I think I’d look to possibly tweak the fan speed. Put simply, I think I’d rather have less noise at the expense of slightly higher CPU temps. Any way you look at it though, the Scythe Mugen 5 gives a really solid level of performance.