I happend to buy Instant Orchestra (I already got GPO) and updated the ARIA Player.
There are some problems that should be addressed in time:
Loading an GPO patch leads to an strange sfz info page instead of a GPO page (like it does if you load a IO patch).
The smallest sample preload is 32kb - this is not necessary with an SSD. We need smaller preload options here probabaly down to 6kb.
The name of a loaded ensemble vanishes in some hosts as soon as the projekt is saved. Only in the latest Vienna Ensemble Pro version the ensemble name stays visible. In Reaper and Studio One 2 the ensemble patch name will be replaced with "-" after the patch is loaded and the projekt saved in the DAW.
RAM use per AU or VSTi instance is outrageous. The libraries are so small that they easily fit into Ram of a normal PC/Mac but using many instances or ARIA to have all sounds loaded use Gigabytes of Ram. When you load the whole library ARIA uses more Ram than the samples of the patches. This should be significantly lower. This is possible - look at GPlayer which uses very little Ram.
The Giga import is still missing. It was promised in a newsletter one year ago and I am - and many VSL users are really longing for this.
IO is advertised as addon product to GPO. While this is a good fit the patches are quite different programmed. All GPO sounds use much less reverb than the IO patches. The panning is also different in some patches. The two libraries could blend a lot better if GPO would get a patch set that is tailored to work with IO.
These are some points, detected after using the new ARIA version for one day.