I don't regret for a second either purchase! I still have them both, mostly to listen to tracks I produced with them. I never reached those heights when I was using it. To the question of what can you do with it, well, there are some absolutely brilliant demos, I can't even imagine the hours required to produce these tracks. If you just want to learn about MIDI orchestration/arranging I still think GPO and JABB are good tools. The Jazz & Big Band 3 sampled sound library integrates the uniquely powerful and high-performance ARIA Player. You'll spend more money to purchase them, and you'll spend more time learning to use them. Garritan Jazz & Big Band 3 features the jazz sounds, ranges, and techniques required to make your music swing with the authenticity of a real jazz or big band group. There are much better libraries out there today. I started with the original version of each and upgraded each time, in the hopes that they would get better, and I suppose they did, at some level. Such flexibility, such tone, what a price tag! And difficult to use? You bet! So GPO and later JABB were a bit of a breath of fresh air. Any key, any instrument combinations, 3 staves, 10 staves, doesnt matter. I had purchased Garritan Orchestral Strings and it was awesome. Secondly I might be 'off topic', but in the bands I play in, they presented a piece today that has a 7/8 section, SOOOOOO, if anybody has some relatively simple not kindergarten, but not 'advanced' either 7/8 tunes, could you send me a copy, either in PM, or in email. To put things in perspective - at the time GigaStudio ruled the world. It really seems as if Gary set out to build a learning tool. I thought both of them were brilliant learning tools! While the sounds may not be quite as good (in some cases) or nearly as broad as those found in the Kontakt Factory Library they are organized in such a way that you will learn a lot about MIDI orchestration and arranging.
And it requires the Aria player, which has not received a lot of attention in the ensuing years. And you will be limited in the articulations you can choose from. The samples in both GPO and JABB run the gamut from brilliant to poor, which is very unfortunate.