Lightroom has the Clarity slider (for local contrast enhancement) which AP doesn't have, despite requests to Bibble Labs, the original creators of the program. It might be possible to reproduce this with a sharpening plugin, using the regular sharpening set to 1 to 2 pixels radius, and the plugin set to something more like 20-40. But if you don't need Clarity, you don't need Lightroom. Besides, Adobe Camera Raw has a Clarity slider.
Anyway, I have been using the program on and off (more off than on) since I bought Bibble version 4 and got the free upgrade to version 5 (had to pay for AP, though, albeit with a discount). I haven't had it crash so far, but I only use the Linux version now and again to save having to reboot into Windows.
The only thing I can suggest is that you ask in the Corel Aftershot Pro forum
. If you're using 64-bit Windows 7, there's a thread
there that might interest you.