I am looking again at Albion as a potential orchestral upgrade from GPO4. I've watched the videos and received feedback on the Virtual Instruments Control forum, so I have a good idea as to how to evaluate the library on it's own, but what I don't know is how successfully it is being used within Sonar X1. Is there anyone here who has experience with it and can contribute some comments on it's suitability for me as an X1 user?

I've been using for some time now and as a Kontakt library it works well with X1. No real technical issues have come up. They only things you need to consider with Albion is that the instrument patches are unison ensemble patches which might not bend to every situation. Other than that I've found it really fantastic to work with and it's pretty much replaced the other orchestral libraries I have (Vienna Special Edition, KIrk Hunter SO, K4 VSL library). Personally I'm looking for to the release of Albion II since it seems to have a lot of stuff that is "missing" in Albion. If you need a lot of solo instruments then Albion is probably not the right choice.

Thanks, Kuusniemi, those comments are very helpful.

Albion looks good. I decided on Orchestral Essentials instead because of its larger, more epic sound, IMO. Both would be nice to have, however, if one could afford that luxury.

No problems using Albion in X1 here either. As Kussniemi mentioned it's not a bread & butter library like VSL or EW.
If you're looking for that type of library it's fantastic.