When I first tried this thing I didn't like it. It sounded horrid to me, very cheap (yeah I know a mellotron is supposed to sound a little canned). When I stumbled across these reviews, I thought I better give it a second chance. Nope, still don't like it. Maybe mine is broke, I think. So I downloaded again and reinstalled. Sorry, not to be a downer but this thing sounds awful.
If you play a triad on the strings in the middle register, it sounds good and you think "wow, a real mellotron". When you play the high or low registers you start to hear the badly looped sample, the digital artifacts, and the slight out-of-tuneness. And the other sounds are even worse than the strings.
I don't understand why this has gotten so many accolades so far. I respect the fact that it's free (gave it a ten for value; hey if it's worth anything, it's a great value), I'm no snob believe me I use almost all freebies; but this thing just sounds bad to me, and I've almost never found a use for it. I hope this isn't considered insulting or libelous. I'm just being honest. It's free so don't believe me; download it yourself and decide if I'm wrong or not.

A very nice instrument -- what could be better than a free mellotron? While it doesn't go so far as M-tron in striving for the perfect emulation, it does offer an identifiable "mellotron" sound.
UI -- nice & small with no unnecessary bells & whistles, nice mellotron-style dials
sound -- pretty much described above
features -- only three sounds (but look at a real mellotron). Control over tone and attack & decay (I don't *think* the mellotron had these) and a "quality" control for that classic crappy tape sound :)
docs -- none
presets -- bare bones
support -- never needed
vfm -- 10 of course
stability -- no problems here

I own all tape banks for the M-Tron, but I´m surprised that the strings of MelloSound are sounding different than all the strings- and violin-sounds of the M-Tron. They are more soft and dreamy than the M-Tron sounds, what I personally like very much. Also the samples are looped very good, so there is no limitation to a 8 seconds sound.

It´s a very nice instrument for free.

What a remarkable, useful instrument! Between this and Big Tick's Cheeze Machine, one has an awesome arsenal to create unbelievable sounding pads. The interface is sparse--big deal, though, given how cool it sounds. It has only three presets: strings, brass, and choir--all of which can be tweaked with the "quality" knob. This let's you control how "lo-fi" you want the sound to be. It also has the requisite attack and decay knobs. The pinch here is that you only have three options for these: short, medium, and long. I've found these are just fine. I only wish it had the most famous of mellotron sounds (Strawberry Fields). Hopefully an update will provide that flute sound. All that said, this is a such fantastically usable instrument, you'd be crazy not to download it.

[This is an amendment to my review. I've now used this fabulous vsti for a few months. Since I've been using it, I've heard other CDs that have the same exact sound, making me think that the word is out on this instrument. The new Opeth CD (Damnation) has Mellotron strings and choir all over it. Word is that Steven Wilson from Porcupine Tree (who produced this disc) loves the Mellotron and played the vintage keyboard on the Opeth CD. My point is that it sounds EXACTLY like Mellosound! Personally, I think that he just said he used a real one to sound cool and retro. :) It would have been a hell of a lot easier just to use Mellosound. A fantastic plug-in, especially when complemented with MultiLens.]