I eagerly downloaded 3.3 as soon as it was available - the idea of a shared library/format between iPhoto and Aperture is great - sharing Faces/Places etc.
But I haven't been able to do anything with it yet! After the initial library conversion, once I'd gone into Aperture it started generating previews for my entire collection - about 50,000 images - not sure why this was necessary - since the previews were there before the upgrade.
I've had the activity window more or less permanently open since I did the upgrade last week, and there are still over 8,000 previews to go - hopefully by the weekend it will have finished and I'll actually be able to try out some of the new features.
While doing this preview generation, Aperture hangs periodically (and never seems to recover requiring a force quit and restart) when it tries simultaenously to sync the Facebook albums.
I mention all this because unlike with the previous version, when if there was some activity to carry out, if you started to use Aperture, the activities would pause - this doesn't seem to happen now - or at least the application is so busy with the background activity, that it doesn't seem possible to kick off an action that might make it suspend background activity.
Doesn't look like a stable release to me so far - although maybe after this questionable preview re-generation I'll find a different story - has anyone else encountered this behaviour?