A while back, I had reviewed this in the forums and I gave it a good score. Now I regret having done that, because purchasing this software was an expensive mistake.
First off, MSI comes with a PACE iLok dongle. As I said in my old review, this is a piece of crap, and as I used MSI more, it got worse - to the point where my PC would freeze because of this thing after every third time I tried to choose an instrument. PACE has pretty much screwed over everyone who buys this software. Maybe it'll be fixed in an update... but I'm not waiting around to find out.
User Interface: MSI's main redeeming quality is its GUI. This is probably as good as it's going to get right now. Everything you need to tweak a sample is right in front of you. Hit one button and you can go into key-switching and crossfading, etc. Great.
Sound: Some of MSI sounds good. It comes with a lot of extras you might find useful (like a ton of wonderfully sampled recorder instruments), but unfortunately where it counts (strings, brass, woodwinds) this thing falls flat on its face. Basically many of the instruments have attacks that're WAY too slow. Not to mention the strings aren't multisampled enough, so you're plagued with vibrato problems and really obvious rosin noise (friend, who's not a musician, even noticed it and said it sounded real bad) in many of the violin and viola ensemble and solo instruments. The strings aren't completely unusable, but don't expect this to be the be-all and end-all of budget orchestra. The brass (most of it) is excellent for the most part, no real complaints except for pitch ranges (see below). The woodwinds are a joke, though. The flute is out of tune on certain samples and again, some of the attacks are too slow. The woodwind ensembles are terrible. The clarinet is okay and so is the oboe, but they aren't great. The brass and woodwinds have pitch ranges that're WAY too narrow. The oboe is missing about 8 notes from its pitch range. What gives, MOTU!? That's bull! The overall quality of the sound is good for the price, but there're too many unforgivable little quirks that make it largely unusable as a stand-alone orchestral instrument.
Features: Good filters, good tremolo effect, good EQ. If you're unhappy with the french horn solo sample (like I was) just run it through a lowpass filter some and you got yourself a pretty basic french horn patch that sounds the way a solo french horn should. You shouldn't have to do this in the first place, but whatever.
Documentation: Decent. Great that it offers a few tables that tell you how much memory each sample takes up.
Presets: Like I said before, they're largely unusable. To get the most out of this instrument, tweak your own stuff.
Customer Support: MOTU's customer support is great when you can get a hold of them. Also Unicornation's MSI forum has a bunch of people who are willing to help if you have a problem.
Value for Money: 300 dollars for something I can't really use? I don't need to go into this anymore.
Stability: What a joke. Granted, MSI itself doesn't freeze my PC, PACE iLok does.