I switched to digital only this year, and LR was the software I picked for RAW conversion reasons and speed (LR is much more forgiving if you haven't got the latest and best hardware).
It is an extreme pleasure to work with, and more than once I added a session just after midnight ("just one more image") , but finally worked until four in the morning.
LR has issues, but that's normal in early versions. They aren't crippling.
Hardware demands are up with 1.1, that's for sure. My G5 iMac 2.1 Ghz is getting slow with its single processor, but it's still fun.
Issues:
1. cyclically the loading times of images go up to six seconds, and after a while go back to 2 seconds when you leave the application, and restart it (or for some other reason, sometimes it speeds up all by itself again)
2. Library and develop modul less separated. I would like to have access to Metadata in develop.
3. A compare feature of snapshots in develop.
This is all no reason to say goodbye.
I just hope they will fix point 1) soon.
If you look at Aperture, you can't see the curve to really adjust contrast, just the contrast slider, there is no vibrance, and I like the screen appearance of Lightroom more. It's just more elegant.
So, Macgyver, maybe this is just a moment of frustration everybody experiences once in a while, but I guess it's more your old G4 that deserves it than this application.