Welcome to the forum. I know you will enjoy GPO once it is in your hands and computer. Your question is interesting. GPO is like many things in life, i.e. the rewards you get are directly proportional to the amount of effort you put into it.
If you are a somewhat skilled musician you will probably find it easy, if not, you may have some learning to do. I would say that GPO is intuitive. Like any good tool, it feels good when you use it. It does not force you to deal with its encumbrances, for it has few if any. So it becomes almost transparent, and lets you focus on your music.
No matter what your skill level, you will find GPO a joy to use. If you are a musician from the start, you can create superb music almost from the start. If you are a novice musician, you will find exploring and developing your new craft a real joy.
If you are in any way in need of help, or just want to talk about things GPO and sometimes things not GPO, that’s what we do here. We invite you to join in. Hope to hear your music as you progress with GPO.
It's like anything else, it depends on how much experience have you had creating recordings, that started out as midi performances... There's a lot of work that's necessary for the execution of phrases to make it sound like the real instrument, particularly in the strings... Then there's also the mix, how you use effects, panning, and eq... So, yeah, it helps that you have a good sound library... But a great sound library is only half of the equation, the other half is the writing, the recording, the mixing...
Also, I want to add, to really get great recordings of any sound library, after you've done all your midi work, record each track as audio and then mix and effect the audio files... That's how you're ultimately going to get the best results out of any sound library...
Well... actually i'm playing a piano for 7 years... and i love it... but i've got to do the composing with just a mouse. Because my keyboard doesn't have modulation and a good midi input so... I heard you get Cubase with GPO. If so... is it easy to work with only a mouse... or is a notation program necessary?