Wow! This one has gone on a bit. Sorry if I'm a bit late to the party and many thanks to David H for the recommendation much, much earlier in the thread. :D
Here's my take on it all as a professional TV composer and only semi-pro videographer. I may be the most guilty one here for wanting to dabble in all the various creative technologies (music, photography, video, graphic design, animation) - it's great fun and if I can save a few quid and make a satisfactory job of it then it's all good. But if the project was important to me I wouldn't pretend to be professional at anything other than composing music.
All the loop-based music creation programs are great for getting quick and dirty tracks together and if you have an ear for it and the style suits the images well then you may well be in business. But it's really music by numbers and there is unlikely to be much real musicality going on - fine for dance tracks I guess but you can't (yet) create an evolving, emotive orchestral score or let's say an acoustic guitar piece that is really going to move anyone.
Listening to the Garritan effort I'm afraid I had to cringe, because although the piano sample was much better than the MIDI version it was still a rather clunky performance and I was waiting all the time for the orchestra to come in and amaze me. Of course it didn't, because any attempt to recreate an orchestral version in 3 minutes would sound...well it would sound like it was done in 3 minutes!
Don't get me wrong Garritan is a decent orchestral library but you need to be a good musician to create good music with it - there's no quick fix. There's also the fact that many professional composers are using far more intricate and expensive sound libraries to create scores that can now be used on real, full-scale movies in place of an orchestra - you'll find a number tracks made with them at our new download site (see my signature). My own latest orchestral library was purchased for just under $12,000. You may be very interested to hear the realism of these product demos
http://www.vsl.co.at/en-us/67/4587/4851.vsl. But using it is an art form in itself - it's deep, very, very deep.
As for Royalty Free Music being generally poor (as was alluded to earlier), in some cases one has to say it's true but people used to talk the same way about TV Production Library Music from the likes of Chappell and Carlin in the early days. Again, it's true to some extent that a lot of it was created on crappy synths by musicians and composers who were never going to make it writing for major TV themes and films, but the producers saying that didn't always realise that there were a great many fantastic albums by the likes of Jonathan Butler, Martin Taylor, Brian Bennett and George Fenton on the shelves, followed later by Harry Gregson-Williams and now Hans Zimmer for goodness sake!
Coming back to Royalty Free Music (and as an ambassador of it) I'm not afraid to mention some of my competitors here who have some quite outstanding music on their sites for ridiculously paltry sums. Go and listen to The Music Bakery, The Beat Suite....oh... I almost forgot....then come and visit
http://www.2b-royaltyfree.com and hear some truly outstanding rock and dramatic, developing orchestral music from Pierre Langer, some wonderfully characterful pieces by Jerome Lamasset (and, if you must, some other stuff by myself) and walk away with exactly what you need for a silly amount of money, without all the hassle of trying to learn the history and theory of music composition in one night, then go and sell 5000 copies of your film and make your fortune.
The better libraries have made royalty-free music ludicrously cheap for the experience, time investment and quality that you're buying and you can use it time and again. Find a good supplier and spend all your spare time refining what you're really good at - making great films.
Sorry, did I go on a bit? X-D
Kind regards to all,
Colin