I'm a long-time and regular user of XLD and have come to appreciate its features and versatility. I've come to depend on it for yielding the best possible audio results.
I was recently asked my opinion of MediaHuman Audio Converter for compressing flac to AAC/m4a. So I did some A/B comparisons. The results were rather dramatic. For comparison I use Spek, as well as the Plot Spectrum feature in Audacity.
True to form, XLD yields audio spectrum results that are as close to the original flac as one could hope for (btw, this is only possible if you compress to AAC - mp3 isn't capable of that).
The conversion with MH yields results which would lead one to believe it's actually using an mp3 codec instead of AAC, with the sharp 20kHz cutoff characteristic of mp3.
If you plot spectrum of the vast majority of iTunes Store purchases you'll find that the spectrum extends to a minimum of 21kHz, and many extend to 22kHz. Granted, the human ear can't hear above 20kHz anyway, and that was the original rational used by the standards bodies when they came up with mp3 in 1993 in the first place. For that reason mp3 filters everything above 20kHz. But it was long ago discovered that the original thinking was flawed because it doesn't take into spacial characteristics (sound stage) and high frequency harmonic distortion, etc.
Part of the reason AAC sounds better than mp3 is it has superior audio spectrum. AAC is a lossy format, but nearly as lossy as mp3. MH eliminates that AAC advantage altogether by, apparently, imposing its own 20kHz filter on AAC conversions, and I can't condemn that in strong enough words. Regardless of how nice the user interface and how easy it is to use, I won't be using or recommending it.
For those who are still compressing to mp3 (which is a really foolish thing to do in this day and age -- mp3 was abandoned years ago by the standards bodies in favor of AAC because of mp3's mediocre performance characteristics), MH might be a simple and easy to use option. But again, you really shouldn't be compressing to mp3 in the first place, unless you're one of the few who still has an "mp3 player" that doesn't support AAC.