As I understand it, IO is intended as a library for quick and easy orchestral mockups. So, instead of having individual instruments which the user can then build into an ensemble, IO contains a variety of pre-built ensembles and samples that the user can use to make an orchestral sounding piece without having to be an expert at orchestration.
In other words, IO does not make GPO obsolete in the slightest. I only own IO myself (and the garritan instruments included with Finale) and find it very useful, but if you are a composer that wants complete control over every piece in your virtual orchestra, GPO is probably still the way to go.
IO is great for cinematic mockups, but if you're writing music for live performance by a real orchestra, it probably will not serve your purposes as well as GPO. On the flip side, IO does have some great percussion and effects samples, so if you write music that requires those kinds of sounds, it's a good investment.
I think Garritan considers IO to be a complement to GPO as opposed to being a replacement.
It does not make GPO obsolete.
Better samples, no. Different samples, yes.
Ease of use, it's easier because different sounds are already layered together. You still have to write your own music though, it doesn't do it for you.
Your sound with GPO will not change simply if you buy IO. If you use them together, you'll get a different sound.
The big difference being, with GPO you get individual instruments. (1st violins, 2nd violins, oboe, flute, etc...)
With IO, for instance you'll get all strings loaded into a single patch, playing a certain style or technique. Or you get a combination of brass and strings layered together.
Bottom line, if you compose 100% in a traditional way, where you write every note for every instrument, then stick with GPO. But, if you are open to composing in a different way, using these combined patches as sound design, then I"m sure you'll enjoy IO.
Good question, good responses - thank you aflocka and Jeff for giving Scaramouche all the answers I was ready to write before I saw your responses. You both made it very clear what the differences are between IO and GPO.
To underline - IO doesn't make GPO "obsolete" in the least. It's a very different program, but one that compliments GPO.
The video tutorials will help to explain - Here's the direct link to part one at YouTube:
Thanks rbowser, I will check them out. I am for one glad that I purchased IO. I listened to other libraries before making the purchase such as ewqlso gold and I have to say IO has that old classical feel that I like. Not saying the other libraries aren't good or nothing, but they tend to be more hollywood-like which is still different than that WWII old feel! I hope Garry releases the 24 bit version of IO. Thanks again. Oh, and I am also glad that there is NO ILOK. That is what prevented me form purchasing the EWQL Solo Violin.